Add readme and use protonlabs package namespace

Author: BafS

Readme.md

@@ -0,0 +1,23 @@
+# Proton PHP Coding Standards
+
+## Installation & Usage
+
+Install the package with composer
+
+```sh
+composer req protonlabs/php-coding-standard --dev
+```
+
+To use it in your phpcs xml, add a rule pointing to the ruleset.xml
+
+```xml
+<?xml version="1.0"?>
+<ruleset name="ProtonLabs PHP CodeSniffer Standard">
+    <!-- Proton Coding Standard – https://github.com/ProtonMail/php-coding-standard -->
+    <rule ref="vendor/protonlabs/php-coding-standard/Proton/ruleset.xml">
+        <!-- sniffs to exclude -->
+    </rule>
+
+    <exclude-pattern>*/vendor/*</exclude-pattern>
+</ruleset>
+```

composer.json

@@ -1,13 +1,17 @@
 {
-    "name": "proton/php-coding-standard",
+    "name": "protonlabs/php-coding-standard",
     "description": "ProtonMail Coding Standard",
     "type": "phpcodesniffer-standard",
+    "keywords": [
+        "php-codesniffer", "coding-standard"
+    ],
+    "homepage": "https://github.com/ProtonMail/php-coding-standard",
     "minimum-stability": "dev",
     "prefer-stable": true,
     "require": {
         "php": "^7.1",
         "slevomat/coding-standard": "^4.8",
-        "squizlabs/php_codesniffer": "^3.3.0"
+        "squizlabs/php_codesniffer": "^3.3"
     },
     "license": "MIT"
 }