[feature] provide `OwnerName` field for README template (#10981)

Co-Authored-By: 6543 <6543@obermui.de>
Co-authored-by: techknowlogick <techknowlogick@gitea.io>

docs/content/doc/advanced/customizing-gitea.en-us.md

@@ -236,7 +236,7 @@ Locales may change between versions, so keeping track of your customized locales
 To add a custom Readme, add a markdown formatted file (without an `.md` extension) to `custom/options/readme`
 
 **NOTE:** readme templates support **variable expansion**.  
-currently there are `{Name}` (name of repository), `{Description}`, `{CloneURL.SSH}` and `{CloneURL.HTTPS}`
+currently there are `{Name}` (name of repository), `{Description}`, `{CloneURL.SSH}`, `{CloneURL.HTTPS}` and `{OwnerName}`
 
 ### Reactions
 

modules/repository/init.go

@@ -55,6 +55,7 @@ func prepareRepoCommit(ctx models.DBContext, repo *models.Repository, tmpDir, re
 		"Description":    repo.Description,
 		"CloneURL.SSH":   cloneLink.SSH,
 		"CloneURL.HTTPS": cloneLink.HTTPS,
+		"OwnerName":      repo.OwnerName,
 	}
 	if err = ioutil.WriteFile(filepath.Join(tmpDir, "README.md"),
 		[]byte(com.Expand(string(data), match)), 0644); err != nil {