feat: enable buildkite by default

lib/config/definitions.js

@@ -839,7 +839,6 @@ const options = [
     stage: 'repository',
     type: 'json',
     default: {
-      enabled: false,
       fileMatch: ['\\.buildkite/.+\\.yml$'],
       commitMessageTopic: 'buildkite plugin {{depName}}',
       commitMessageExtra: 'to {{newVersion}}',

test/config/__snapshots__/index.spec.js.snap

@@ -26,7 +26,6 @@ Object {
   "buildkite": Object {
     "commitMessageExtra": "to {{newVersion}}",
     "commitMessageTopic": "buildkite plugin {{depName}}",
-    "enabled": false,
     "fileMatch": Array [
       "\\\\.buildkite/.+\\\\.yml$",
     ],

website/docs/configuration-options.md

@@ -150,10 +150,10 @@ This field is combined with `branchPrefix` and `managerBranchPrefix` to form the
 
 Configuration specific for buildkite plugins updates.
 
-| name    | value                                                 |
-| ------- | ----------------------------------------------------- |
-| type    | object                                                |
-| default | { enabled: false, managerBranchPrefix: 'buildkite-' } |
+| name    | value                                 |
+| ------- | ------------------------------------- |
+| type    | object                                |
+| default | { managerBranchPrefix: 'buildkite-' } |
 
 ## bumpVersion