English language revisions to home page texts

Most of these are very straightforward grammar fixes. Changing the name of the “Release and tips blogs” further reading link creates a mismatch between the name of the Doc, which is still “Release and tips blogs”, and the link text, which I changed to “Release notes and tips”. I still suggest making the change, and will also submit a PR for `release_and_tips_blogs.md` to propose the same change.
Merge pull request #1 from acusti/patch-1

English language revisions to home page texts