Add API for gitignore templates (#22783)

This implements the [Gitignores template API of GitHub](https://docs.github.com/en/rest/gitignore?apiVersion=2022-11-28) in Gitea

routers/api/v1/swagger/misc.go

@@ -14,6 +14,20 @@ type swaggerResponseServerVersion struct {
 	Body api.ServerVersion `json:"body"`
 }
 
+// GitignoreTemplateList
+// swagger:response GitignoreTemplateList
+type swaggerResponseGitignoreTemplateList struct {
+	// in:body
+	Body []string `json:"body"`
+}
+
+// GitignoreTemplateInfo
+// swagger:response GitignoreTemplateInfo
+type swaggerResponseGitignoreTemplateInfo struct {
+	// in:body
+	Body api.GitignoreTemplateInfo `json:"body"`
+}
+
 // LicenseTemplateList
 // swagger:response LicenseTemplateList
 type swaggerResponseLicensesTemplateList struct {