Implement a schema for IPv4 addresses (#2)

Signed-off-by: Juan Cruz Viotti <jv@jviotti.com>

Author: jviotti

schemas/ietf/ip/v4/address.json

@@ -0,0 +1,17 @@
+{
+  "$schema": "https://json-schema.org/draft/2020-12/schema",
+  "title": "RFC 3986 IPv4 Address",
+  "description": "An Internet Protocol version 4 address in dotted-decimal notation",
+  "$comment": "https://www.rfc-editor.org/rfc/rfc3986#section-3.2.2",
+  "examples": [
+    "0.0.0.0",
+    "127.0.0.1",
+    "192.168.1.1",
+    "255.255.255.255",
+    "10.0.0.1"
+  ],
+  "x-license": "https://github.com/sourcemeta/std/blob/main/LICENSE",
+  "type": "string",
+  "pattern": "^([0-9]|[1-9][0-9]|1[0-9]{2}|2[0-4][0-9]|25[0-5])\\.([0-9]|[1-9][0-9]|1[0-9]{2}|2[0-4][0-9]|25[0-5])\\.([0-9]|[1-9][0-9]|1[0-9]{2}|2[0-4][0-9]|25[0-5])\\.([0-9]|[1-9][0-9]|1[0-9]{2}|2[0-4][0-9]|25[0-5])$",
+  "format": "ipv4"
+}