Add migration guide

MIGRATION.md

@@ -0,0 +1,117 @@
+# Migration guide
+
+This repository was renamed from **rir-ip** to **country-ip-blocks**.
+
+## Migration steps
+
+1. If only consuming raw text files: just update the download URL, no code changes needed
+2. Update repository URLs in your code from `ipverse/rir-ip` to `ipverse/country-ip-blocks`
+3. If parsing JSON: handle field renames (see below)
+
+## What's changing
+
+### Repository name
+- Old: `ipverse/rir-ip`
+- New: `ipverse/country-ip-blocks`
+
+### File structure
+
+The file structure remains the same:
+```
+country/ad/aggregated.json
+country/ad/ipv4-aggregated.txt
+country/ad/ipv6-aggregated.txt
+```
+
+### JSON format
+
+**Old:**
+```json
+{
+  "country": "Andorra",
+  "country-code": "AD",
+  "delegation-status": [
+    "allocated",
+    "assigned"
+  ],
+  "mode": "aggregated",
+  "subnets": {
+    "ipv4": [
+      "46.172.224.0/19",
+      "85.94.160.0/19"
+    ],
+    "ipv6": [
+      "2a01:fb00::/29"
+    ]
+  }
+}
+```
+
+**New:**
+```json
+{
+  "country": "Andorra",
+  "countryCode": "AD",
+  "delegationStatus": [
+    "allocated",
+    "assigned"
+  ],
+  "exportMode": "aggregated",
+  "prefixes": {
+    "ipv4": [
+      "46.172.224.0/19",
+      "85.94.160.0/19"
+    ],
+    "ipv6": [
+      "2a01:fb00::/29"
+    ]
+  }
+}
+```
+
+**Changes:**
+- `country-code` renamed to `countryCode`
+- `delegation-status` renamed to `delegationStatus`
+- `mode` renamed to `exportMode`
+- `subnets` renamed to `prefixes`
+
+### TXT format
+
+The text file format remains the same:
+
+ipv4-aggregated.txt:
+```
+# Country: Andorra (AD)
+# Address family: IPv4
+# Delegation status: Allocated || Assigned
+# Export mode: Aggregated
+#
+46.172.224.0/19
+85.94.160.0/19
+```
+
+ipv6-aggregated.txt:
+```
+# Country: Andorra (AD)
+# Address family: IPv6
+# Delegation status: Allocated || Assigned
+# Export mode: Aggregated
+#
+2a01:fb00::/29
+```
+
+### URL changes
+
+**Old:**
+```
+https://raw.githubusercontent.com/ipverse/rir-ip/master/country/ad/aggregated.json
+https://raw.githubusercontent.com/ipverse/rir-ip/master/country/ad/ipv4-aggregated.txt
+https://raw.githubusercontent.com/ipverse/rir-ip/master/country/ad/ipv6-aggregated.txt
+```
+
+**New:**
+```
+https://raw.githubusercontent.com/ipverse/country-ip-blocks/master/country/ad/aggregated.json
+https://raw.githubusercontent.com/ipverse/country-ip-blocks/master/country/ad/ipv4-aggregated.txt
+https://raw.githubusercontent.com/ipverse/country-ip-blocks/master/country/ad/ipv6-aggregated.txt
+```