Swagger.v1.json template (#3572)

* Turn swagger.v1.json into template

* Rename ENABLE_SWAGGER_ENDPOINT option to ENABLE_SWAGGER

routers/swagger_json.go

@@ -0,0 +1,14 @@
+package routers
+
+import (
+	"code.gitea.io/gitea/modules/base"
+	"code.gitea.io/gitea/modules/context"
+)
+
+// tplSwaggerV1Json swagger v1 json template
+const tplSwaggerV1Json base.TplName = "swagger/v1_json"
+
+// SwaggerV1Json render swagger v1 json
+func SwaggerV1Json(ctx *context.Context) {
+	ctx.HTML(200, tplSwaggerV1Json)
+}