Git _Help.rst: Add commit squashing explanation
Git _Help.rst: Add commit squashing explanation

Fixes https://github.com/coala-analyzer/coala/issues/1789

scottbelden/coala,Uran198/coala,abhiroyg/coala,kartikeys98/coala,abhiroyg/coala,coala-analyzer/coala,incorrectusername/coala,tushar-rishav/coala,stevemontana1980/coala,d6e/coala,stevemontana1980/coala,ManjiriBirajdar/coala,SanketDG/coala,vinc456/coala,Asalle/coala,Asalle/coala,NiklasMM/coala,ayushin78/coala,nemaniarjun/coala,djkonro/coala,swatilodha/coala,netman92/coala,tushar-rishav/coala,Nosferatul/coala,rimacone/testing2,sagark123/coala,CruiseDevice/coala,swatilodha/coala,yashtrivedi96/coala,mr-karan/coala,sagark123/coala,refeed/coala,NiklasMM/coala,Shade5/coala,Uran198/coala,sophiavanvalkenburg/coala,SanketDG/coala,Asnelchristian/coala,karansingh1559/coala,arush0311/coala,rimacone/testing2,Asnelchristian/coala,saurabhiiit/coala,Nosferatul/coala,refeed/coala,sophiavanvalkenburg/coala,swatilodha/coala,dagdaggo/coala,mr-karan/coala,djkonro/coala,NalinG/coala,vinc456/coala,nemaniarjun/coala,NalinG/coala,Nosferatul/coala,sagark123/coala,tushar-rishav/coala,jayvdb/coala,yashLadha/coala,NalinG/coala,shreyans800755/coala,stevemontana1980/coala,arjunsinghy96/coala,damngamerz/coala,meetmangukiya/coala,RJ722/coala,abhiroyg/coala,saurabhiiit/coala,NalinG/coala,ayushin78/coala,Balaji2198/coala,svsn2117/coala,nemaniarjun/coala,Asalle/coala,yland/coala,Shade5/coala,sophiavanvalkenburg/coala,ManjiriBirajdar/coala,scottbelden/coala,rresol/coala,coala-analyzer/coala,jayvdb/coala,aptrishu/coala,Balaji2198/coala,JohnS-01/coala,SanketDG/coala,NalinG/coala,NiklasMM/coala,RJ722/coala,yland/coala,netman92/coala,yashtrivedi96/coala,sils1297/coala,netman92/coala,svsn2117/coala,tltuan/coala,aptrishu/coala,coala/coala,JohnS-01/coala,jayvdb/coala,rimacone/testing2,aptrishu/coala,MariosPanag/coala,AbdealiJK/coala,arjunsinghy96/coala,d6e/coala,shreyans800755/coala,AbdealiJK/coala,yashtrivedi96/coala,coala/coala,MariosPanag/coala,incorrectusername/coala,dagdaggo/coala,yashLadha/coala,ayushin78/coala,yland/coala,d6e/coala,incorrectusername/coala,shreyans800755/coala,svsn2117/coala,sils1297/coala,scottbelden/coala,kartikeys98/coala,mr-karan/coala,arush0311/coala,vinc456/coala,Asnelchristian/coala,saurabhiiit/coala,AbdealiJK/coala,damngamerz/coala,dagdaggo/coala,JohnS-01/coala,meetmangukiya/coala,meetmangukiya/coala,NalinG/coala,tltuan/coala,CruiseDevice/coala,MariosPanag/coala,rresol/coala,impmihai/coala,NalinG/coala,ManjiriBirajdar/coala,impmihai/coala,yashLadha/coala,MattAllmendinger/coala,kartikeys98/coala,tltuan/coala,impmihai/coala,coala-analyzer/coala,MattAllmendinger/coala,karansingh1559/coala,Balaji2198/coala,djkonro/coala,MattAllmendinger/coala,arush0311/coala,Shade5/coala,coala/coala,refeed/coala,arjunsinghy96/coala,damngamerz/coala,Uran198/coala,karansingh1559/coala,CruiseDevice/coala,RJ722/coala,rresol/coala,sils1297/coala