Replacing default content with HPCE stuff

- Add README.md
- Customize _config.yml
- /merlin6/ pages (moved from merlin6-user-guide)
- remove demo products
- remove update.sh

README.md

@@ -2,3 +2,39 @@
 
 This site documents the *Merlin 6* cluster at Paul Scherrer Institute.
 Live pages are available at https://lsm-hpce.gitpages.psi.ch/merlin6.
+
+
+## Installation
+
+Building locally requires ruby 2.5 and bundler. To install:
+
+```
+gem install bundler
+bundle install
+```
+
+To run a local webserver:
+
+```
+bundle exec jekyll serve
+```
+
+## Theme
+
+The theme is derived from the
+[Jekyll Doc Theme 6.0](https://github.com/tomjoht/documentation-theme-jekyll)
+by Tom Johnson.
+
+### Organization
+
+- Sidebars are specified in `_data/sidebars/<sidebar>.yml`. Use
+  `sidebar: <sidebar>` in the frontmatter of a page
+- Top Menu is controlled by `_data/topnav.yml`
+
+
+## License
+
+Theme content is licensed under the MIT license.
+The Navgoco jQuery component used in the sidebar is licensed under the BSD
+license.
+See licenses subdirectory for license terms.