chore: apply suggestions from code review

Co-authored-by: ieQu1 <99872536+ieQu1@users.noreply.github.com>

apps/emqx_management/i18n/emqx_mgmt_api_key_i18n.conf

@@ -11,7 +11,7 @@ emqx_mgmt_api_key_schema {
   }
   bootstrap_file {
     desc {
-      en: """Is used to add an api_key when emqx is launched,
+      en: """Bootstrap file is used to add an api_key when emqx is launched,
       the format is:
        ```
        7e729ae70d23144b:2QILI9AcQ9BYlVqLDHQNWN2saIjBV4egr1CZneTNKr9CpK

changes/v5.0.14/feat-9713.en.md

@@ -1,3 +1,3 @@
 Introduce `api_key.bootstrap_file` to initialize the api key at boot time.
 Deprecate `dashboard.bootstrap_users_file`.
-limit the maximum number of api keys to 100 instead of 30.
+Limit the maximum number of api keys to 100 instead of 30.