Documentation tweaks
Documentation tweaks

- Use better grammar (it's -> its)
- Avoid repetition in some places
- Fix and shortify the docker install copy-paste snippet
gsamokovarov/web-console-rails3,rails/web-console,gsamokovarov/web-console-rails3,tabislick/web-console,jmbejar/web-console,tabislick/web-console,gsamokovarov/web-console-rails3,zBMNForks/web-console,slobodankovacevic/web-console,jmbejar/web-console,ryandao/web-console,gsamokovarov/web-console,eileencodes/web-console,gsamokovarov/web-console,sh19910711/web-console,rails/web-console,gsamokovarov/web-console,tabislick/web-console,zBMNForks/web-console,rails/web-console,eileencodes/web-console,eileencodes/web-console,jmbejar/web-console,ryandao/web-console,eileencodes/web-console,gsamokovarov/web-console,ryandao/web-console,sh19910711/web-console,sh19910711/web-console,sh19910711/web-console,slobodankovacevic/web-console,zBMNForks/web-console,zBMNForks/web-console,tabislick/web-console,rails/web-console