Add JSON Schema for .wp-env.json files (WordPress#36276)

Co-authored-by: fabiankaegy <fabiankaegy@git.wordpress.org>
Co-authored-by: ajlende <ajlende@git.wordpress.org>
Co-authored-by: t-hamano <wildworks@git.wordpress.org>
Co-authored-by: gziolo <gziolo@git.wordpress.org>
Co-authored-by: PerryRylance <perryrylance@git.wordpress.org>

schemas/json/.wp-env.json

@@ -0,0 +1,107 @@
+{
+	"title": "JSON schema for WordPress wp-env configuration files",
+	"$schema": "http://json-schema.org/draft-04/schema#",
+	"definitions": {
+		"//": {
+			"reference": "https://developer.wordpress.org/block-editor/reference-guides/packages/packages-env/"
+		},
+		"wpEnvProperties": {
+			"properties": {
+				"core": {
+					"description": "The WordPress installation to use. If null is specified, wp-env will use the latest production release of WordPress.",
+					"default": null,
+					"oneOf": [
+						{
+							"type": "string"
+						},
+						{
+							"type": "null"
+						}
+					]
+				},
+				"phpVersion": {
+					"description": "The PHP version to use. If null is specified, wp-env will use the default version used with production release of WordPress.",
+					"default": null,
+					"oneOf": [
+						{
+							"type": "string"
+						},
+						{
+							"type": "null"
+						}
+					]
+				},
+				"plugins": {
+					"description": "A list of plugins to install and activate in the environment.",
+					"default": [],
+					"type": "array",
+					"items": {
+						"type": "string"
+					}
+				},
+				"themes": {
+					"description": "A list of themes to install in the environment.",
+					"default": [],
+					"type": "array",
+					"items": {
+						"type": "string"
+					}
+				},
+				"port": {
+					"description": "The primary port number to use for the installation. You'll access the instance through the port: 'http://localhost:8888'.",
+					"default": 8888,
+					"type": "integer"
+				},
+				"config": {
+					"description": "Mapping of wp-config.php constants to their desired values.",
+					"default": {},
+					"type": "object"
+				},
+				"mappings": {
+					"description": "Mapping of WordPress directories to local directories to be mounted in the WordPress instance.",
+					"default": {},
+					"type": "object"
+				}
+			}
+		}
+	},
+	"type": "object",
+	"allOf": [
+		{
+			"$ref": "#/definitions/wpEnvProperties"
+		},
+		{
+			"properties": {
+				"$schema": {
+					"type": "string"
+				},
+				"env": {
+					"description": "The key env is available to override any of the above options on an individual-environment basis.",
+					"type": "object",
+					"default": {},
+					"patternProperties": {
+						"[a-zA-Z]": {
+							"type": "object",
+							"$ref": "#/definitions/wpEnvProperties",
+							"additionalProperties": false
+						}
+					}
+				}
+			}
+		},
+		{
+			"properties": {
+				"$schema": {},
+				"core": {},
+				"phpVersion": {},
+				"plugins": {},
+				"themes": {},
+				"port": {},
+				"config": {},
+				"mappings": {},
+				"env": {}
+			},
+			"additionalProperties": false
+		}
+	]
+}