Add the missing capitalisation to the docstring.

PiperOrigin-RevId: 767667182
Change-Id: I854d8ed04dbeb7256906383ab29c1cca95e7ea53
diff --git a/cc/cc_toolchain_config_lib.bzl b/cc/cc_toolchain_config_lib.bzl
index 876ed4d..a1f5694 100644
--- a/cc/cc_toolchain_config_lib.bzl
+++ b/cc/cc_toolchain_config_lib.bzl
@@ -394,7 +394,7 @@
             explicitly marks it as unsupported.
         flag_sets: A FlagSet list - If the given feature is enabled, the flag
             sets will be applied for the actions are specified for.
-        env_sets: an EnvSet list - If the given feature is enabled, the env
+        env_sets: An EnvSet list - If the given feature is enabled, the env
             sets will be applied for the actions they are specified for.
         requires: A list of feature sets defining when this feature is
             supported by the  toolchain. The feature is supported if any of the