Tweak the grammar of some titles in bazel documentation.

RELNOTES: None.
PiperOrigin-RevId: 178406494
diff --git a/site/docs/install-compile-source.md b/site/docs/install-compile-source.md
index 03c72fb..1bee1e1 100644
--- a/site/docs/install-compile-source.md
+++ b/site/docs/install-compile-source.md
@@ -1,9 +1,9 @@
 ---
 layout: documentation
-title: Compile Bazel from Source
+title: Compiling Bazel from Source
 ---
 
-# <a name="compiling-from-source"></a>Compile Bazel from source
+# <a name="compiling-from-source"></a>Compiling Bazel from Source
 
 You can build Bazel from source following these steps:
 
diff --git a/site/docs/install-os-x.md b/site/docs/install-os-x.md
index 5318344..fe2c0f8 100644
--- a/site/docs/install-os-x.md
+++ b/site/docs/install-os-x.md
@@ -3,9 +3,9 @@
 title: Installing Bazel on macOS
 ---
 
-# <a name="mac-os-x"></a>Install Bazel on macOS (OS X)
+# <a name="mac-os-x"></a>Installing Bazel on macOS
 
-Install Bazel on macOS (OS X) using one of the following methods:
+Install Bazel on macOS using one of the following methods:
 
 *   [Use Homebrew (recommended)](#install-on-mac-os-x-homebrew)
 *   [Use the binary installer](#install-with-installer-mac-os-x)
@@ -16,17 +16,17 @@
 *   access the [bash completion script](install.md)
 *   install the [zsh completion script](install.md)
 
-## <a name="install-on-mac-os-x-homebrew"></a>Install using Homebrew
+## <a name="install-on-mac-os-x-homebrew"></a>Installing using Homebrew
 
 ### 1. Install JDK 8
 
 JDK 8 can be downloaded from [Oracle's JDK
 Page](http://www.oracle.com/technetwork/java/javase/downloads/jdk8-downloads-2133151.html).
 
-Look for "Mac OS X" under "Java SE Development Kit". This will download a DMG
+Look for "macOS" under "Java SE Development Kit". This will download a DMG
 image with an install wizard.
 
-### 2. Install Homebrew on macOS (OS X)
+### 2. Install Homebrew on macOS
 
 Installing Homebrew is a one-time setup:
 
@@ -53,7 +53,7 @@
 brew upgrade bazel
 ```
 
-## <a name="install-with-installer-mac-os-x"></a>Install using binary installer
+## <a name="install-with-installer-mac-os-x"></a>Installing using binary installer
 
 The binary installers are on Bazel's [GitHub releases page](https://github.com/bazelbuild/bazel/releases).
 
diff --git a/site/docs/install-redhat.md b/site/docs/install-redhat.md
index 9c4f65c..a7ce4e5 100644
--- a/site/docs/install-redhat.md
+++ b/site/docs/install-redhat.md
@@ -3,14 +3,14 @@
 title: Installing Bazel on Fedora and CentOS
 ---
 
-# Install Bazel on Fedora and CentOS
+# Installing Bazel on Fedora and CentOS
 
 The Bazel team does not provide official packages for Fedora and CentOS.
 Vincent Batts [@vbatts](https://github.com/vbatts) generously maintains
 unofficial packages on
 [Fedora COPR](https://copr.fedorainfracloud.org/coprs/vbatts/bazel/).
 
-## Install Bazel on Fedora 25, 26
+## Installing Bazel on Fedora 25, 26
 
 1. Install `dnf` and the `copr` plugin if you have not already done so.
 
@@ -21,7 +21,7 @@
    dnf install bazel
    ```
 
-## Install Bazel on CentOS 7
+## Installing Bazel on CentOS 7
 
 1. Download the corresponding `.repo` file from [Fedora COPR](https://copr.fedorainfracloud.org/coprs/vbatts/bazel/)
    and copy it to `/etc/yum.repos.d/`.
diff --git a/site/docs/install-ubuntu.md b/site/docs/install-ubuntu.md
index 3da518c3..ce93022 100644
--- a/site/docs/install-ubuntu.md
+++ b/site/docs/install-ubuntu.md
@@ -3,7 +3,7 @@
 title: Installing Bazel on Ubuntu
 ---
 
-# <a name="ubuntu"></a>Install Bazel on Ubuntu
+# <a name="ubuntu"></a>Installing Bazel on Ubuntu
 
 Supported Ubuntu Linux platforms:
 
@@ -60,7 +60,7 @@
 sudo apt-get upgrade bazel
 ```
 
-## <a name="install-with-installer-ubuntu"></a>Install using binary installer
+## <a name="install-with-installer-ubuntu"></a>Installing using binary installer
 
 The binary installers are on Bazel's [GitHub releases page](https://github.com/bazelbuild/bazel/releases).
 
diff --git a/site/docs/install-windows.md b/site/docs/install-windows.md
index a5019ae..857e2a4 100644
--- a/site/docs/install-windows.md
+++ b/site/docs/install-windows.md
@@ -3,7 +3,7 @@
 title: Installing Bazel on Windows
 ---
 
-# <a name="windows"></a>Install Bazel on Windows
+# <a name="windows"></a>Installing Bazel on Windows
 
 Supported Windows platforms:
 
diff --git a/site/docs/rule-challenges.md b/site/docs/rule-challenges.md
index 23737cd..1d39695 100644
--- a/site/docs/rule-challenges.md
+++ b/site/docs/rule-challenges.md
@@ -1,9 +1,9 @@
 ---
 layout: documentation
-title: Challenges of Writing Rules.
+title: Challenges of Writing Rules
 ---
 
-# Challenges of Writing Rules.
+# Challenges of Writing Rules
 
 We have heard feedback from various people that they have
 difficulty to write efficient Bazel rules. There is no single root cause, but
diff --git a/site/docs/skylark/performance.md b/site/docs/skylark/performance.md
index b7a88b4..4538bfd 100644
--- a/site/docs/skylark/performance.md
+++ b/site/docs/skylark/performance.md
@@ -1,9 +1,9 @@
 ---
 layout: documentation
-title: Performance
+title: Optimizing Performance
 ---
 
-# Performance
+# Optimizing Performance
 
 <!-- [TOC] -->
 
diff --git a/site/docs/tutorial/android-app.md b/site/docs/tutorial/android-app.md
index a049f22..f016628 100644
--- a/site/docs/tutorial/android-app.md
+++ b/site/docs/tutorial/android-app.md
@@ -3,7 +3,7 @@
 title: Build Tutorial - Android
 ---
 
-Introduction to Bazel: Build an Android App
+Introduction to Bazel: Building an Android App
 ==========
 
 In this tutorial, you will learn how to build a simple Android app. You'll do
diff --git a/site/docs/tutorial/cpp.md b/site/docs/tutorial/cpp.md
index 32ac4f6..f757bfd 100644
--- a/site/docs/tutorial/cpp.md
+++ b/site/docs/tutorial/cpp.md
@@ -3,7 +3,7 @@
 title: Build Tutorial - C++
 ---
 
-Introduction to Bazel: Build a C++ Project
+Introduction to Bazel: Building a C++ Project
 ==========
 
 In this tutorial, you'll learn the basics of building C++ applications with
diff --git a/site/docs/tutorial/ios-app.md b/site/docs/tutorial/ios-app.md
index 17f1ffb..dba5b55 100644
--- a/site/docs/tutorial/ios-app.md
+++ b/site/docs/tutorial/ios-app.md
@@ -3,7 +3,7 @@
 title: Build Tutorial - iOS
 ---
 
-Introduction to Bazel: Build an iOS App
+Introduction to Bazel: Building an iOS App
 ==========
 
 In this tutorial, you will learn how to build a simple iOS app. You'll do the
diff --git a/site/docs/tutorial/java.md b/site/docs/tutorial/java.md
index e273776..8b4a482 100644
--- a/site/docs/tutorial/java.md
+++ b/site/docs/tutorial/java.md
@@ -3,7 +3,7 @@
 title: Build Tutorial - Java
 ---
 
-Introduction to Bazel: Build a Java Project
+Introduction to Bazel: Building a Java Project
 ==========
 
 In this tutorial, you'll learn the basics of building Java applications with