Codestyle.md: Correct parameter name in example
Codestyle.md: Correct parameter name in example

The documentation example mentioned area of rectangle as
height * breadth but the documentation was mentioned as
length in place of height, Ideally it should be length and
product with height. This patch fixes the documentation for
this problem.

Fixes https://github.com/coala-analyzer/coala/issues/1269

yashtrivedi96/coala,aptrishu/coala,vinc456/coala,d6e/coala,rimacone/testing2,scottbelden/coala,Asnelchristian/coala,svsn2117/coala,ayushin78/coala,svsn2117/coala,NalinG/coala,sudheesh001/coala,d6e/coala,Asnelchristian/coala,Uran198/coala,NalinG/coala,RJ722/coala,scottbelden/coala,scriptnull/coala,nemaniarjun/coala,AbdealiJK/coala,jayvdb/coala,sudheesh001/coala,abhiroyg/coala,yland/coala,swatilodha/coala,ayushin78/coala,Nosferatul/coala,mr-karan/coala,yashLadha/coala,Shade5/coala,JohnS-01/coala,yashtrivedi96/coala,Uran198/coala,tltuan/coala,swatilodha/coala,Balaji2198/coala,netman92/coala,NalinG/coala,lonewolf07/coala,yland/coala,MariosPanag/coala,arush0311/coala,tushar-rishav/coala,SanketDG/coala,NalinG/coala,coala-analyzer/coala,rresol/coala,NiklasMM/coala,tltuan/coala,arjunsinghy96/coala,saurabhiiit/coala,AdeshAtole/coala,mr-karan/coala,nemaniarjun/coala,karansingh1559/coala,arjunsinghy96/coala,sophiavanvalkenburg/coala,SambitAcharya/coala,yashLadha/coala,AdeshAtole/coala,scriptnull/coala,vinc456/coala,nemaniarjun/coala,aptrishu/coala,refeed/coala,SanketDG/coala,meetmangukiya/coala,lonewolf07/coala,RJ722/coala,djkonro/coala,JohnS-01/coala,RJ722/coala,JohnS-01/coala,svsn2117/coala,Asalle/coala,jayvdb/coala,scriptnull/coala,incorrectusername/coala,CruiseDevice/coala,dagdaggo/coala,SambitAcharya/coala,mr-karan/coala,sagark123/coala,AbdealiJK/coala,impmihai/coala,incorrectusername/coala,CruiseDevice/coala,impmihai/coala,incorrectusername/coala,AdeshAtole/coala,scriptnull/coala,sophiavanvalkenburg/coala,AbdealiJK/coala,shreyans800755/coala,Balaji2198/coala,coala/coala,NalinG/coala,netman92/coala,tushar-rishav/coala,Asnelchristian/coala,dagdaggo/coala,refeed/coala,shreyans800755/coala,ayushin78/coala,tltuan/coala,coala-analyzer/coala,swatilodha/coala,karansingh1559/coala,aptrishu/coala,dagdaggo/coala,scottbelden/coala,tushar-rishav/coala,NalinG/coala,arush0311/coala,arafsheikh/coala,sagark123/coala,saurabhiiit/coala,vinc456/coala,rresol/coala,MattAllmendinger/coala,Balaji2198/coala,stevemontana1980/coala,SambitAcharya/coala,sophiavanvalkenburg/coala,sils1297/coala,Nosferatul/coala,sils1297/coala,arjunsinghy96/coala,meetmangukiya/coala,NiklasMM/coala,impmihai/coala,MariosPanag/coala,rimacone/testing2,MariosPanag/coala,arafsheikh/coala,jayvdb/coala,Uran198/coala,damngamerz/coala,damngamerz/coala,yland/coala,scriptnull/coala,arush0311/coala,rimacone/testing2,coala-analyzer/coala,abhiroyg/coala,karansingh1559/coala,yashLadha/coala,coala/coala,rresol/coala,Shade5/coala,Nosferatul/coala,stevemontana1980/coala,saurabhiiit/coala,djkonro/coala,damngamerz/coala,ManjiriBirajdar/coala,sagark123/coala,SambitAcharya/coala,sudheesh001/coala,scriptnull/coala,Shade5/coala,lonewolf07/coala,SanketDG/coala,coala/coala,refeed/coala,djkonro/coala,CruiseDevice/coala,scriptnull/coala,SambitAcharya/coala,kartikeys98/coala,shreyans800755/coala,NalinG/coala,yashtrivedi96/coala,meetmangukiya/coala,stevemontana1980/coala,d6e/coala,MattAllmendinger/coala,abhiroyg/coala,Asalle/coala,NiklasMM/coala,kartikeys98/coala,MattAllmendinger/coala,kartikeys98/coala,ManjiriBirajdar/coala,sils1297/coala,SambitAcharya/coala,SambitAcharya/coala,netman92/coala,ManjiriBirajdar/coala,arafsheikh/coala,Asalle/coala