Add documentation about Gitaly concurrency limiter
Add documentation about Gitaly concurrency limiter

stoplightio/gitlabhq,stoplightio/gitlabhq,stoplightio/gitlabhq,mmkassem/gitlabhq,mmkassem/gitlabhq,mmkassem/gitlabhq,stoplightio/gitlabhq,mmkassem/gitlabhq