Document cc_toolchain to avoid unnecessary builds
Document that tags = ["manual"] should be used.
Fixes
RELNOTES:none
@@ -400,4 +400,8 @@ public final class CcToolchainRule implements RuleDefinition {
page
</a> for elaborate C++ toolchain configuration and toolchain selection documentation.
</p>
+<p>
+ Use <code>tags = ["manual"]</code> in order to prevent toolchains from being built and configured
+ unnecessarily when invoking <code>bazel build //...</code>
+</p>
<!-- #END_BLAZE_RULE -->*/
