docs(Readme): Move out legacy API docs

Author: cblanc

LEGACY.md

@@ -0,0 +1,43 @@
+### Legacy API
+
+Below documents the old validation API, which continues to be supported.
+
+Create an instance of Postcode to perform utility methods, like so:
+
+```javascript
+const Postcode = require("postcode");
+
+const postcode = new Postcode("ec1v9lb");
+```
+
+Perform simple validations, parsing and normalisation
+
+```javascript
+postcode.valid()        // => true
+postcode.normalise()    // => "EC1V 9LB"
+
+postcode.outcode()      // => "EC1V"
+postcode.incode()       // => "9LB"
+postcode.area()         // => "EC"
+postcode.district()     // => "EC1"
+postcode.subDistrict()  // => "EC1V"
+postcode.sector()       // => "EC1V 9"
+postcode.unit()         // => "LB"
+```
+
+### Method Overview
+
+| Postcode | .outcode() | .incode() | .area() | .district() | .subDistrict() | .sector() | .unit() |
+|----------|------------|-----------|---------|-------------|----------------|-----------|---------|
+| AA9A 9AA | AA9A       | 9AA       | AA      | AA9         | AA9A           | AA9A 9    | AA      |
+| A9A 9AA  | A9A        | 9AA       | A       | A9          | A9A            | A9A 9     | AA      |
+| A9 9AA   | A9         | 9AA       | A       | A9          | null           | A9 9      | AA      |
+| A99 9AA  | A99        | 9AA       | A       | A99         | null           | A99 9     | AA      |
+| AA9 9AA  | AA9        | 9AA       | AA      | AA9         | null           | AA9 9     | AA      |
+| AA99 9AA | AA99       | 9AA       | AA      | AA99        | null           | AA99 9    | AA      |
+
+### Misc. Class Methods include
+
+```javascript
+Postcode.validOutcode(outcode)
+```

README.md

@@ -5,7 +5,7 @@
 > Validate & parse UK postcodes
 
 [![CircleCI](https://circleci.com/gh/ideal-postcodes/postcode.svg?style=svg)](https://circleci.com/gh/ideal-postcodes/postcode)
-[![Coverage Status](https://coveralls.io/repos/github/ideal-postcodes/postcode/badge.svg?branch=master)](https://coveralls.io/github/ideal-postcodes/postcode?branch=master) 
+[![Coverage Status](https://coveralls.io/repos/github/ideal-postcodes/postcode/badge.svg?branch=master)](https://coveralls.io/github/ideal-postcodes/postcode?branch=master)
 [![Dependencies](https://david-dm.org/ideal-postcodes/postcode.svg)](https://david-dm.org/ideal-postcodes/postcode)
 [![Size](https://img.shields.io/bundlephobia/min/postcode.svg?style=flat)](https://bundlephobia.com/result?p=postcode)
 [![Downloads](https://img.shields.io/npm/dm/postcode.svg)](https://www.npmjs.com/package/postcode)
@@ -116,49 +116,9 @@ Postcode.toSector("Sw1A 2aa");      // => "SW1A 2"
 Postcode.toUnit("Sw1A 2aa");        // => "AA"
 ```
 
-### Older API
+### Legacy API
 
-Below documents the old validation API, which continues to be supported.
-
-Create an instance of Postcode to perform utility methods, like so:
-
-```javascript
-const Postcode = require("postcode");
-
-const postcode = new Postcode("ec1v9lb");
-```
-
-Perform simple validations, parsing and normalisation
-
-```javascript
-postcode.valid()        // => true
-postcode.normalise()    // => "EC1V 9LB"
-
-postcode.outcode()      // => "EC1V"
-postcode.incode()       // => "9LB"
-postcode.area()         // => "EC"
-postcode.district()     // => "EC1"
-postcode.subDistrict()  // => "EC1V"
-postcode.sector()       // => "EC1V 9"
-postcode.unit()         // => "LB"
-```
-
-### Method Overview
-
-| Postcode | .outcode() | .incode() | .area() | .district() | .subDistrict() | .sector() | .unit() |
-|----------|------------|-----------|---------|-------------|----------------|-----------|---------|
-| AA9A 9AA | AA9A       | 9AA       | AA      | AA9         | AA9A           | AA9A 9    | AA      |
-| A9A 9AA  | A9A        | 9AA       | A       | A9          | A9A            | A9A 9     | AA      |
-| A9 9AA   | A9         | 9AA       | A       | A9          | null           | A9 9      | AA      |
-| A99 9AA  | A99        | 9AA       | A       | A99         | null           | A99 9     | AA      |
-| AA9 9AA  | AA9        | 9AA       | AA      | AA9         | null           | AA9 9     | AA      |
-| AA99 9AA | AA99       | 9AA       | AA      | AA99        | null           | AA99 9    | AA      |
-
-### Misc. Class Methods include
-
-```
-Postcode.validOutcode(outcode)
-```
+The legacy object based API is documented in [LEGACY.md](LEGACY.md)
 
 ## Definitions