Fix typos in all docs [skip ci]

doc/api/settings.md

@@ -57,7 +57,7 @@ Parameters:
 - `default_project_visibility` - what visibility level new project receives
 - `default_snippet_visibility` - what visibility level new snippet receives
 - `restricted_signup_domains` - force people to use only corporate emails for signup
-- `user_oauth_applications` - allow users to create oauth applicaitons
+- `user_oauth_applications` - allow users to create oauth applications
 - `after_sign_out_path` - where redirect user after logout
 All parameters are optional. You can send only one that you want to change.

doc/development/db_dump.md

-# Importing a database dump into a staging enviroment
+# Importing a database dump into a staging environment
 Sometimes it is useful to import the database from a production environment
 into a staging environment for testing. The procedure below assumes you have

doc/raketasks/backup_restore.md

@@ -360,8 +360,8 @@ If you are using backup restore procedures you might encounter the following war
 ```
 psql:/var/opt/gitlab/backups/db/database.sql:22: ERROR:  must be owner of extension plpgsql
-psql:/var/opt/gitlab/backups/db/database.sql:2931: WARNING:  no privileges could be revoked for "public" (two occurences)
-psql:/var/opt/gitlab/backups/db/database.sql:2933: WARNING:  no privileges were granted for "public" (two occurences)
+psql:/var/opt/gitlab/backups/db/database.sql:2931: WARNING:  no privileges could be revoked for "public" (two occurrences)
+psql:/var/opt/gitlab/backups/db/database.sql:2933: WARNING:  no privileges were granted for "public" (two occurrences)
 ```

doc/release/monthly.md

@@ -176,7 +176,7 @@ Tweet about the RC release:
 1. Also check the CI changelog
 1. Add a proposed tweet text to the blog post WIP MR description.
 1. Create a WIP MR for the blog post
-1. Make sure merge request title starts with `WIP` so it can not be accidently merged until ready.
+1. Make sure merge request title starts with `WIP` so it can not be accidentally merged until ready.
 1. Ask Dmitriy (or a team member with OS X) to add screenshots to the WIP MR.
 1. Decide with core team who will be the MVP user.
 1. Create WIP MR for adding MVP to MVP page on website

doc/web_hooks/web_hooks.md

@@ -184,7 +184,7 @@ X-Gitlab-Event: Note Hook
 {
   "object_kind": "note",
   "user": {
-    "name": "Adminstrator",
+    "name": "Administrator",
     "username": "root",
     "avatar_url": "http://www.gravatar.com/avatar/e64c7d89f26bd1972efa854d13d7dd61?s=40\u0026d=identicon"
   },
@@ -337,7 +337,7 @@ X-Gitlab-Event: Note Hook
 {
   "object_kind": "note",
   "user": {
-    "name": "Adminstrator",
+    "name": "Administrator",
     "username": "root",
     "avatar_url": "http://www.gravatar.com/avatar/e64c7d89f26bd1972efa854d13d7dd61?s=40\u0026d=identicon"
   },