docs: Add indexing limitation on files with lines over 4096 bytes (#32205)

Co-authored-by: Alex Nguyen <150945400+nguyenalex836@users.noreply.github.com>

content/search-github/github-code-search/about-github-code-search.md

@@ -30,6 +30,7 @@ The current limitations on indexed code are:
 - Only UTF-8 encoded files are included
 - Very large repositories may not be indexed
 - Exhaustive search is not supported
+- Files with more than one line over 4096 bytes are excluded
 
 We currently only support searching for code on the default branch of a repository. The query length is limited to 1000 characters.