pull definition up, add more explicit carve-out, reduce redundancy

Fixes #48

Changes to titles of paragraphs 3, 4, and 7

…s in section 1

- added a should have known standard as further movement on balance of interests discussed in #38 and in the initial PR comment above
- Exhibit A moved to standalone documentation to make the agreement more adaptable
- removed grant to use name as included in material Company can use; deemed unnecessary
- added duty to not use or disclose to Company anything that you're required not to (to avoid muddying Company IP; note this is _not_ a duty to keep Company materials confidential, removed in earlier commits because almost always covered by other agreements)
- added survivorship clause (if any terms found invalid, others remain in effect)
- further README edits to better reflect v2