RELEASE_NOTES.rst: Add 0.9.1 release notes
RELEASE_NOTES.rst: Add 0.9.1 release notes

(cherry picked from commit a60b5767b7faea0346e3c0258230d9ea5b2d2694)

JohnS-01/coala,meetmangukiya/coala,meetmangukiya/coala,yashtrivedi96/coala,JohnS-01/coala,shreyans800755/coala,rimacone/testing2,sagark123/coala,JohnS-01/coala,arjunsinghy96/coala,refeed/coala,incorrectusername/coala,impmihai/coala,SanketDG/coala,SanketDG/coala,ayushin78/coala,NiklasMM/coala,sagark123/coala,Shade5/coala,jayvdb/coala,refeed/coala,Nosferatul/coala,yashtrivedi96/coala,yashtrivedi96/coala,yashLadha/coala,RJ722/coala,refeed/coala,SanketDG/coala,aptrishu/coala,MariosPanag/coala,ayushin78/coala,meetmangukiya/coala,shreyans800755/coala,yashLadha/coala,nemaniarjun/coala,CruiseDevice/coala,NiklasMM/coala,damngamerz/coala,Balaji2198/coala,karansingh1559/coala,Asnelchristian/coala,jayvdb/coala,damngamerz/coala,coala-analyzer/coala,aptrishu/coala,damngamerz/coala,yashLadha/coala,coala/coala,aptrishu/coala,jayvdb/coala,kartikeys98/coala,arush0311/coala,impmihai/coala,coala-analyzer/coala,netman92/coala,arjunsinghy96/coala,NiklasMM/coala,netman92/coala,Asnelchristian/coala,Shade5/coala,Asnelchristian/coala,Asalle/coala,arush0311/coala,MariosPanag/coala,MariosPanag/coala,karansingh1559/coala,Nosferatul/coala,sagark123/coala,Asalle/coala,Nosferatul/coala,impmihai/coala,coala-analyzer/coala,Asalle/coala,rimacone/testing2,coala/coala,arjunsinghy96/coala,nemaniarjun/coala,Balaji2198/coala,coala/coala,nemaniarjun/coala,CruiseDevice/coala,RJ722/coala,kartikeys98/coala,kartikeys98/coala,rimacone/testing2,CruiseDevice/coala,netman92/coala,Shade5/coala,RJ722/coala,incorrectusername/coala,arush0311/coala,Balaji2198/coala,ayushin78/coala,incorrectusername/coala,shreyans800755/coala,karansingh1559/coala