reworked hoodie.store.md

- replaced 'data' with 'object(s)'
- moved scoped store api to the bottom
- removed scoped store from examples and just left hoodie.store.add etc
- changed type:add to just add
- added clear event
- added the options parameter to all methods, because I think that every
  method should be fully self-explanatory and not require to read another
  part of the documentation first
- Removed complex example that used  callback before
- findAll, updateAll, removeAll do not require a type right now, technically.
  But it's considered harmful as objects will be affected that might be used
  internally only, and therefore I'd rather say it is.
- I left out the validate method, as it's not really usable yet. But we
  will add it back in soon, esp. as option to the scoped store as sugested
  by Dennis (love the idea)
fix(hoodie.store): removed validate from index
fix(hoodie.store): adding store.on() to index
chore(hoodie.store): updated wording data with object
Merge pull request #75 from hoodiehq/gregor_store_api_feedback

reworked hoodie.store.md