Update text domain and add WPCS for i18n

.gitignore

@@ -41,4 +41,5 @@ jspm_packages/
 # Assets build directory
 assets/build/**/*.css
 assets/build/**/*.map
-assets/build/**/*.js
+assets/build/**/*.js
+/vendor/

.phpcs.xml.dist

@@ -0,0 +1,26 @@
+<?xml version="1.0"?>
+<ruleset>
+	<!-- Check all PHP files in directory tree by default. -->
+	<arg name="extensions" value="php"/>
+	<file>.</file>
+
+	<!-- Exclude package files -->
+	<exclude-pattern>/vendor/*</exclude-pattern>
+	<exclude-pattern>/node_modules/*</exclude-pattern>
+
+	<!-- Confirm PHP compat. -->
+	<config name="testVersion" value="7.4-"/>
+	<rule ref="PHPCompatibilityWP" />
+
+    <!-- Display sniff code -->
+    <arg value="s"/>
+
+	<rule ref="WordPress" phpcbf-only="true" />
+    <rule ref="WordPress.WP.I18n">
+		<properties>
+			<property name="text_domain" type="array">
+				<element value="secure-custom-fields"/>
+			</property>
+		</properties>
+	</rule>
+</ruleset>

composer.json

@@ -0,0 +1,20 @@
+{
+    "name": "wordpress/secure-custom-fields",
+    "description": "Secure Custom Fields",
+    "type": "project",
+    "license": "GPL-2.0-or-later",
+    "authors": [
+        {
+            "name": "WordPress.org"
+        }
+    ],
+    "config": {
+        "allow-plugins": {
+            "dealerdirect/phpcodesniffer-composer-installer": true
+        }
+    },
+    "require-dev": {
+        "wp-coding-standards/wpcs": "^3.0",
+        "phpcompatibility/phpcompatibility-wp": "^2.1"
+    }
+}