fix InitCommand() (#285)

split modules/config

login_tasks.go should probably be modules/task/login.go,
but i didn't do that, as it still depends on the global
`Config` variable from the config module, see
https://gitea.com/gitea/tea/issues/158

rework InitCommand()

- make it error tolerant if $PWD is not a git repo (#200)
- don't force default login when repo flag is set (#191)

remove InitCommandLoginOnly()

Merge branch 'master' into issue-200-initcommand

improve docs

Merge branch 'master' into issue-200-initcommand

move config func and config task func to right place

Co-authored-by: Norwin Roosen <git@nroo.de>
Co-authored-by: 6543 <6543@obermui.de>
Reviewed-on: https://gitea.com/gitea/tea/pulls/285
Reviewed-by: 6543 <6543@obermui.de>
Reviewed-by: khmarbaise <khmarbaise@noreply.gitea.io>
Co-Authored-By: Norwin <noerw@noreply.gitea.io>
Co-Committed-By: Norwin <noerw@noreply.gitea.io>

cmd/flags/flags.go

@@ -34,7 +34,7 @@ var LoginFlag = cli.StringFlag{
 var RepoFlag = cli.StringFlag{
 	Name:        "repo",
 	Aliases:     []string{"r"},
-	Usage:       "Repository to interact with. Optional",
+	Usage:       "Override local repository path or gitea repository slug to interact with. Optional",
 	Destination: &GlobalRepoValue,
 }