Update content and presentation of website

Tweak links on `index.html`. Add a links to the phrases "maintain software" and
"edit the wiki", pointing to the author's software packages and wiki edits,
respectively. Remove the link from "Arch Linux", which formerly pointed to the
Arch website. The author hopes that this is not a sign of excessive egoism.

Add padding to the image to prevent text from butting up against it. Make the
body of the site 40em wide instead of 35em, which makes paragraphs a more
attractive width. Make links relative (e.g. "./styles.css").

Update README to accomodate changes that have been made to the site.