Remove docs for versions with low usage

See https://packagist.org/packages/doctrine/doctrine-migrations-bundle/stats#major/3

Author: greg0ire

.doctrine-project.json

@@ -45,51 +45,6 @@
       "name": "3.2",
       "slug": "3.2",
       "maintained": false
-    },
-    {
-      "name": "3.1",
-      "slug": "3.1",
-      "maintained": false
-    },
-    {
-      "name": "3.0",
-      "slug": "3.0",
-      "maintained": false
-    },
-    {
-      "name": "2.2",
-      "slug": "2.2",
-      "maintained": true
-    },
-    {
-      "name": "2.1",
-      "slug": "2.1",
-      "maintained": false
-    },
-    {
-      "name": "2.0",
-      "slug": "2.0",
-      "maintained": false
-    },
-    {
-      "name": "1.3",
-      "slug": "1.3",
-      "maintained": false
-    },
-    {
-      "name": "1.2",
-      "slug": "1.2",
-      "maintained": false
-    },
-    {
-      "name": "1.1",
-      "slug": "1.1",
-      "maintained": false
-    },
-    {
-      "name": "1.0",
-      "slug": "1.0",
-      "maintained": false
     }
   ]
 }

.symfony.bundle.yaml

@@ -1,6 +1,4 @@
 branches:
-  - "3.0.x"
-  - "3.1.x"
   - "3.2.x"
   - "3.3.x"
   - "3.4.x"