Add docs for skip_virtual_includes (#920)

Closes #920

COPYBARA_INTEGRATE_REVIEW=https://github.com/bazelbuild/rules_cc/pull/920 from keith:ks/add-docs-for-skip_virtual_includes 0e834a4b430dc19aac0990a39f83174dfa5d05c3
PiperOrigin-RevId: 994315342
Change-Id: Iab7ea501f9c35ad434a11cec1ff31c73ce566222

docs/features.md

diff --git a/docs/features.md b/docs/features.md
index b12569d..ef453cc 100644
--- a/docs/features.md
+++ b/docs/features.md
@@ -538,6 +538,23 @@
 
 This feature must be enabled by default if desired.
 
+### `skip_virtual_includes`
+
+A marker feature that avoids creating `_virtual_includes` symlinks when
+headers only need a `strip_include_prefix` (without an
+`include_prefix`). Instead, `rules_cc` adds the stripped directory to
+the include paths directly and uses the original headers. This reduces
+path lengths and can help avoid long path issues on Windows.
+
+The only downside of this feature is that if you disable sandboxing
+non-declared headers can be included that are in the same directory as
+the one being added to the include path. This would still be caught by
+[`layering_check`](#layering_check) if enabled.
+
+See also [`shorten_virtual_includes`](#shorten_virtual_includes).
+
+This feature must be enabled if desired.
+
 ### `static_link_cpp_runtimes`
 
 A marker feature used by `rules_cc` to determine if the toolchain