Merge branch 'docs-aqualls-20200303-code' into 'master'

Docs: Fix code blocks to add language

See merge request gitlab-org/gitlab!26423

doc/integration/twitter.md

@@ -64,7 +64,7 @@ To enable the Twitter OmniAuth provider you must register your application with
 
    For installations from source:
 
-   ```
+   ```yaml
      - { name: 'twitter', app_id: 'YOUR_APP_ID',
        app_secret: 'YOUR_APP_SECRET' }
    ```

doc/integration/ultra_auth.md

@@ -60,7 +60,7 @@ To get the credentials (a pair of Client ID and Client Secret), you must registe
 
    For installation from source:
 
-   ```
+   ```yaml
    - { name: 'ultraauth',
        app_id: 'OPENID_CLIENT_ID',
        app_secret: 'OPENID_CLIENT_SECRET',

doc/integration/vault.md

@@ -36,7 +36,7 @@ The following assumes you already have Vault installed and running.
 
     You should see the following output in the terminal:
 
-    ```shell
+    ```plaintext
     Success! Enabled oidc auth method at: oidc/
     ```
 
@@ -113,7 +113,7 @@ The following assumes you already have Vault installed and running.
 
     The terminal will output:
 
-    ```
+    ```plaintext
     Success! You are now authenticated. The token information displayed below
     is already stored in the token helper. You do NOT need to run "vault login"
     again. Future Vault requests will automatically use this token.

doc/raketasks/import.md

@@ -98,7 +98,7 @@ To support importing bare repositories from hashed storage, GitLab 10.4 and
 later stores the full project path with each repository, in a special section of
 the Git repository's config file. This section is formatted as follows:
 
-```
+```ini
 [gitlab]
   fullpath = gitlab-org/gitlab
 ```
@@ -128,7 +128,7 @@ Until then, you may wish to manually migrate repositories yourself. You can use
 [Rails console](https://docs.gitlab.com/omnibus/maintenance/#starting-a-rails-console-session)
 to do so. In a Rails console session, run the following to migrate a project:
 
-```
+```ruby
 project = Project.find_by_full_path('gitlab-org/gitlab')
 project.write_repository_config
 ```
@@ -136,7 +136,7 @@ project.write_repository_config
 In a Rails console session, run the following to migrate all of a namespace's
 projects (this may take a while if there are 1000s of projects in a namespace):
 
-```
+```ruby
 namespace = Namespace.find_by_full_path('gitlab-org')
 namespace.send(:write_projects_repository_config)
 ```