Add TOC to yaml README and an intro section
Add TOC to yaml README and an intro section

[ci skip]

daiyu/gitlab-zh,openwide-java/gitlabhq,stoplightio/gitlabhq,screenpages/gitlabhq,shinexiao/gitlabhq,darkrasid/gitlabhq,jirutka/gitlabhq,dplarson/gitlabhq,htve/GitlabForChinese,SVArago/gitlabhq,t-zuehlsdorff/gitlabhq,dplarson/gitlabhq,dreampet/gitlab,dwrensha/gitlabhq,larryli/gitlabhq,mmkassem/gitlabhq,stoplightio/gitlabhq,darkrasid/gitlabhq,openwide-java/gitlabhq,jirutka/gitlabhq,mr-dxdy/gitlabhq,mmkassem/gitlabhq,htve/GitlabForChinese,screenpages/gitlabhq,jirutka/gitlabhq,Soullivaneuh/gitlabhq,dwrensha/gitlabhq,htve/GitlabForChinese,mr-dxdy/gitlabhq,stoplightio/gitlabhq,axilleas/gitlabhq,dplarson/gitlabhq,darkrasid/gitlabhq,Soullivaneuh/gitlabhq,dwrensha/gitlabhq,larryli/gitlabhq,iiet/iiet-git,LUMC/gitlabhq,allysonbarros/gitlabhq,Soullivaneuh/gitlabhq,SVArago/gitlabhq,iiet/iiet-git,icedwater/gitlabhq,dwrensha/gitlabhq,screenpages/gitlabhq,larryli/gitlabhq,allysonbarros/gitlabhq,darkrasid/gitlabhq,axilleas/gitlabhq,jirutka/gitlabhq,Soullivaneuh/gitlabhq,axilleas/gitlabhq,mr-dxdy/gitlabhq,icedwater/gitlabhq,martijnvermaat/gitlabhq,mr-dxdy/gitlabhq,openwide-java/gitlabhq,openwide-java/gitlabhq,dplarson/gitlabhq,daiyu/gitlab-zh,daiyu/gitlab-zh,mmkassem/gitlabhq,icedwater/gitlabhq,t-zuehlsdorff/gitlabhq,iiet/iiet-git,htve/GitlabForChinese,mmkassem/gitlabhq,dreampet/gitlab,dreampet/gitlab,SVArago/gitlabhq,axilleas/gitlabhq,martijnvermaat/gitlabhq,shinexiao/gitlabhq,stoplightio/gitlabhq,t-zuehlsdorff/gitlabhq,martijnvermaat/gitlabhq,LUMC/gitlabhq,SVArago/gitlabhq,iiet/iiet-git,shinexiao/gitlabhq,allysonbarros/gitlabhq,screenpages/gitlabhq,larryli/gitlabhq,LUMC/gitlabhq,dreampet/gitlab,LUMC/gitlabhq,shinexiao/gitlabhq,daiyu/gitlab-zh,icedwater/gitlabhq,martijnvermaat/gitlabhq,allysonbarros/gitlabhq,t-zuehlsdorff/gitlabhq