Markdown fix
INTEGRATE: Stability indices for API docs

* dev:
  Markdown fix
  Stability indices for all API sections
  Stability index rendering experiment
  Stability index explanation
  Finetune readme
  Tighter wording in readme
  typo
Improvements to Readme example
Document upcoming Frame.getElement and .addElement changes
Rename: Frame.getElement() --> Frame.get()
Rename: Frame.addElement() --> Frame.add()
INTEGRATE: Rename: Frame.addElement(), getElement() --> add, get

* dev:
  Rename: Frame.addElement() --> Frame.add()
  Rename: Frame.getElement() --> Frame.get()
  Document upcoming Frame.getElement and .addElement changes
  Improvements to Readme example
Frame.add() takes optional nickname
Frame.get() takes optional nickname
INTEGRATE: Frame.get() and Frame.add() take optional nickname

* dev:
  Frame.get() takes optional nickname
  Frame.add() takes optional nickname
QElementList
Frame.getAll()
QElementList documentation
Frame.getAll documentation
INTEGRATE: Frame.getAll()

* dev:
  Frame.getAll documentation
  QElementList documentation
  Frame.getAll()
  QElementList
toDomElement() method made public
INTEGRATE: toDomElement() method made public

* dev:
  toDomElement() method made public
Rename Frame --> QFrame
Rename frame.js --> q_frame.js
Rename frame test files --> q_frame