Minor word and line break tweaks to reach MVC

This work isn't done, nor is it in the right place. However, it
should be done differently after the feature flag is removed, but for
now, let's get it in the docs, period.

doc/user/discussions/index.md

@@ -360,16 +360,18 @@ with a new push.
 Threads are now resolved if a push makes a diff section outdated.
 Threads on lines that don't change and top-level resolvable threads are not resolved.
 
-## Paginated merge request discussions
+## Display paginated merge request discussions
 
 > - [Introduced](https://gitlab.com/gitlab-org/gitlab/-/issues/340172) in GitLab 15.1 [with a flag](../../administration/feature_flags.md) named `paginated_mr_discussions`. Disabled by default.
 > - [Enabled on GitLab.com](https://gitlab.com/gitlab-org/gitlab/-/issues/364497) in GitLab 15.2.
 > - [Enabled on self-managed](https://gitlab.com/gitlab-org/gitlab/-/issues/364497) in GitLab 15.3.
 
 FLAG:
-On self-managed GitLab, by default this feature is available. To hide the feature per project or for your entire instance, ask an administrator to [disable the feature flag](../../administration/feature_flags.md) named `paginated_mr_discussions`.
+On self-managed GitLab, by default this feature is available. To hide the feature
+per project or for your entire instance, ask an administrator to
+[disable the feature flag](../../administration/feature_flags.md) named `paginated_mr_discussions`.
 On GitLab.com, this feature is available.
 
-A merge request can have a lot of discussions. Loading all of them in a single request
+A merge request can have many discussions. Loading them all in a single request
 can be slow. To improve the performance of loading discussions, they are split into multiple
-pages loading sequentially.
+pages, loading sequentially.