docs(badge): add todo badge (#2240)

fix #2236

Signed-off-by: Bo-Yi Wu <[email protected]>

README.md

@@ -10,30 +10,36 @@
 [![Sourcegraph](https://sourcegraph.com/github.com/gin-gonic/gin/-/badge.svg)](https://sourcegraph.com/github.com/gin-gonic/gin?badge)
 [![Open Source Helpers](https://www.codetriage.com/gin-gonic/gin/badges/users.svg)](https://www.codetriage.com/gin-gonic/gin)
 [![Release](https://img.shields.io/github/release/gin-gonic/gin.svg?style=flat-square)](https://github.com/gin-gonic/gin/releases)
+[![TODOs](https://badgen.net/https/api.tickgit.com/badgen/github.com/gin-gonic/gin)](https://www.tickgit.com/browse?repo=github.com/gin-gonic/gin)
 
 Gin is a web framework written in Go (Golang). It features a martini-like API with performance that is up to 40 times faster thanks to [httprouter](https://github.com/julienschmidt/httprouter). If you need performance and good productivity, you will love Gin.
 
 
 ## Contents
 
-- [Installation](#installation)
-- [Quick start](#quick-start)
-- [Benchmarks](#benchmarks)
-- [Gin v1.stable](#gin-v1-stable)
-- [Build with jsoniter](#build-with-jsoniter)
-- [API Examples](#api-examples)
-    - [Using GET,POST,PUT,PATCH,DELETE and OPTIONS](#using-get-post-put-patch-delete-and-options)
+- [Gin Web Framework](#gin-web-framework)
+  - [Contents](#contents)
+  - [Installation](#installation)
+  - [Quick start](#quick-start)
+  - [Benchmarks](#benchmarks)
+  - [Gin v1. stable](#gin-v1-stable)
+  - [Build with jsoniter](#build-with-jsoniter)
+  - [API Examples](#api-examples)
+    - [Using GET, POST, PUT, PATCH, DELETE and OPTIONS](#using-get-post-put-patch-delete-and-options)
     - [Parameters in path](#parameters-in-path)
     - [Querystring parameters](#querystring-parameters)
     - [Multipart/Urlencoded Form](#multiparturlencoded-form)
     - [Another example: query + post form](#another-example-query--post-form)
     - [Map as querystring or postform parameters](#map-as-querystring-or-postform-parameters)
     - [Upload files](#upload-files)
+      - [Single file](#single-file)
+      - [Multiple files](#multiple-files)
     - [Grouping routes](#grouping-routes)
     - [Blank Gin without middleware by default](#blank-gin-without-middleware-by-default)
     - [Using middleware](#using-middleware)
     - [How to write log file](#how-to-write-log-file)
     - [Custom Log Format](#custom-log-format)
+    - [Controlling Log output coloring](#controlling-log-output-coloring)
     - [Model binding and validation](#model-binding-and-validation)
     - [Custom Validators](#custom-validators)
     - [Only Bind Query String](#only-bind-query-string)
@@ -43,10 +49,16 @@ Gin is a web framework written in Go (Golang). It features a martini-like API wi
     - [Bind HTML checkboxes](#bind-html-checkboxes)
     - [Multipart/Urlencoded binding](#multiparturlencoded-binding)
     - [XML, JSON, YAML and ProtoBuf rendering](#xml-json-yaml-and-protobuf-rendering)
-    - [JSONP rendering](#jsonp)
+      - [SecureJSON](#securejson)
+      - [JSONP](#jsonp)
+      - [AsciiJSON](#asciijson)
+      - [PureJSON](#purejson)
     - [Serving static files](#serving-static-files)
     - [Serving data from reader](#serving-data-from-reader)
     - [HTML rendering](#html-rendering)
+      - [Custom Template renderer](#custom-template-renderer)
+      - [Custom Delimiters](#custom-delimiters)
+      - [Custom Template Funcs](#custom-template-funcs)
     - [Multitemplate](#multitemplate)
     - [Redirects](#redirects)
     - [Custom Middleware](#custom-middleware)
@@ -62,8 +74,8 @@ Gin is a web framework written in Go (Golang). It features a martini-like API wi
     - [http2 server push](#http2-server-push)
     - [Define format for the log of routes](#define-format-for-the-log-of-routes)
     - [Set and get a cookie](#set-and-get-a-cookie)
-- [Testing](#testing)
-- [Users](#users)
+  - [Testing](#testing)
+  - [Users](#users)
 
 ## Installation