Fix some typos on the community page.

[juliusiv]

Was reading through the community page and noticed some typos/light fixes.

[process-bot]

Thanks for the pull request! Make sure it satisfies this checklist. My human colleagues will appreciate it!

Here is what to expect next, and if anyone wants to comment, keep these things in mind.

[evancz]

Thanks!

The delay on this is because it was a batch of changes, and I prefer writing don’t with the pretty apostrophe. So in general, changes like this go better if they are broken up into individual pieces. Same as how omnibus legislation is suboptimal :P