docs: add discussion forums to troubleshooting
docs: add discussion forums to troubleshooting

mahori/brew,nandub/brew,EricFromCanada/brew,Homebrew/brew,nandub/brew,sjackman/homebrew,vitorgalvao/brew,reitermarkus/brew,vitorgalvao/brew,mahori/brew,claui/brew,EricFromCanada/brew,JCount/brew,sjackman/homebrew,MikeMcQuaid/brew,EricFromCanada/brew,EricFromCanada/brew,claui/brew,sjackman/homebrew,vitorgalvao/brew,mahori/brew,claui/brew,Homebrew/brew,konqui/brew,reitermarkus/brew,konqui/brew,nandub/brew,konqui/brew,claui/brew,Homebrew/brew,Homebrew/brew,MikeMcQuaid/brew,JCount/brew,mahori/brew,vitorgalvao/brew,MikeMcQuaid/brew,reitermarkus/brew,JCount/brew,reitermarkus/brew,konqui/brew,MikeMcQuaid/brew,sjackman/homebrew,nandub/brew,JCount/brew