Implemented #6: tag pages.
Made add-tag-pages a proc. Page numbering from one

Now the file blog/index.html is followed by blog/index-2.html, not
blog/index-1.html.
Improved bootstrap.thtml perf. Removed dead code.

This optimization reduces the build time for a 500-post blog
by approx. 60%.
Implemented command 'deploy-custom'. README update