just some more typo changes in the docs

[rozek]

Sorry, but my "boy scout" behaviour results in a "stream" of minor changes - I'm just correcting any (trivial) mistakes whenever I get aware of them...

A note on "package-lock.json": actually, I added it to .gitignore and, thus, it should not be part of any pull requests any longer - but it still is. However, "my" changes to it are minimal: just a change of the version number from "0.9.6" to "0.9.7"