Wiki improvement pull request

[saaj]

Because GitHub doesn't support pull requests for its wiki repos, this is a request for manual pull from my fork's wiki repo. Changes in https://github.com/saaj/sqliteviz/wiki:

1. Use wiki page names as link targets instead of full URLs
2. Add table of contents when the page has more than one section
3. Merge pages about inquiries
4. Wrap lines by 80 characters
5. Add a section on pivot tables in SQL
6. Minor spelling, typography and so on

[lana-k]

• You can render any visualisation as an image by clicking

It sounds confusing: the visualisation is already rendered. Would be better use save or download.

• pivot table SQL is more about how to. Because it's more about SQL features, not sqliteviz.

[saaj]

Done in 2797507b.

[lana-k]

pushed