[update] add readme

Author: toxic-johann

README.md

@@ -1,2 +1,121 @@
 # git-prefix-tag
+
 get git tags with prefix
+
+## Install
+
+```sh
+$ npm install git-prefix-tag --save-dev
+```
+
+## Usage
+
+Assume you have tags like below
+
+>4de0361ae9c51f51fb6d3a50addfff6ca2d64a99	refs/tags/dev-v0.0.1
+>9ec697394a8def124f5b7c85e27a991adbff2c86	refs/tags/dev-v0.1.1
+>3dbfd9dbce2f48c68051d025e037b54bc17b015a	refs/tags/dev-v0.1.2
+>5409b3f8b96087d73973efdacc0a290b873612e3	refs/tags/dev-v0.1.3
+>364a61ea754e8150e3bf460bc37709732260a851	refs/tags/prod-v0.1.0
+>a0ebc1571e2c69725877191d688c815701a49e78	refs/tags/prod-v0.1.1
+>a0ebc1571e2c69725877191d688c815701a49e78	refs/tags/sth-werid
+>d5b47d82ecd19b5c19fe2bd28294ad887968a5aa	refs/tags/prod-v0.1.2
+>10817d87a8182d2a72b174ffb70b879555a2b73c	refs/tags/prod-v0.1.3-alpha
+>45a75e99ea1a6c333eadf81bdbfac164f6613955	refs/tags/prod-v0.1.4-beta
+>702139d72160a729854e3adbc62a2955f87e212b	refs/tags/prod-v0.1.5
+>984e86d46ef724d4d06026740624cce5ecdb59fd	refs/tags/prod-v0.1.6-beta
+
+You can use `git-prefix-tag` to fetch the tag you want.
+
+### getLatest
+
+This function definition is below.
+
+```typescript
+function getLatest(prefix: string | regExp | Function, options: {
+    semver: boolean = false,
+    wholeVersion: boolean = false,
+    withPrefix: boolean = false,
+    all: boolean = false,
+})： string | semver {}
+```
+
+You can use getLatest to get the latest version.
+
+```javascript
+const helper = require('git-prefix-tag');
+console.log(helper.getLatest('dev-v')); // 0.1.3
+```
+
+#### Options
+
+There are several options here.
+
+**withPrefix**
+
+You can add withPrefix option to get the whole tag
+
+```javascript
+const helper = require('git-prefix-tag');
+console.log(helper.getLatest('dev-v', { withPrefix: true })); // dev-v0.1.3
+```
+
+**semver**
+
+You can get a semver object.
+
+```javascript
+const helper = require('git-prefix-tag');
+console.log(helper.getLatest('dev-v', { semver: true }));
+/*
+{
+  "semver": {
+    "raw": "0.1.3",
+    "major": 0,
+    "minor": 1,
+    "patch": 3,
+    "prerelease": [],
+    "build": [],
+    "version": "0.1.3"
+  },
+  "wholeVersion": "0.1.3",
+  "prefix": "dev-v",
+  "tag": "dev-v0.1.3",
+  "version": "0.1.3"
+}
+*/
+```
+
+#### Input
+
+you can custom your input
+
+**RegExp**
+
+```javascript
+const helper = require('git-prefix-tag');
+console.log(helper.getLatest(/dev-v/)); // 0.1.3
+```
+
+**Function**
+
+```javascript
+const helper = require('git-prefix-tag');
+console.log(helper.getLatest(() => 'dev-v'))); // 0.1.3
+```
+
+### increase
+
+You can get the increace tag based on the latest tag through this function. Its definition is like this.
+
+```javascript
+function increase(prefix: string | regExp | Function, type: 'major' | 'premajor' | 'minor' | 'preminor' | 'patch' | 'prepatch' | 'prerelease' = 'patch'): string {}
+```
+
+You can use like this.
+
+```javascript
+const helper = require('git-prefix-tag');
+console.log(helper.increase('dev-v')); // '0.1.4'
+console.log(helper.increase('dev-v', 'minor')); // '0.2.0'
+```