V1.0

* New text for the home page
* Announcement
* Extracted install instructions from getting started

/cc @alco @ericmj please review!
Imports: new functions may be added to the Kernel module, which is auto-imported. **They may collide with local functions defined in your modules. Collisions can be resolved using `import Kernel, except: [...]` with a list of all functions you don't want imported from `Kernel`.**

This sounds better IMO, although I can't think of a way to fit the "we reserve the right" phrase into this paragraph. It could go at the beginning, instead of "new functions may be added" say "we reserve the right to add new functions".