PiperOrigin-RevId: 388345855

- introduction to keras for engineers
- introduction to keras for researchers

PiperOrigin-RevId: 380842991

PiperOrigin-RevId: 380209964

PiperOrigin-RevId: 379561296

PiperOrigin-RevId: 347068926

Currently the code is still under development/migration and it is NOT the source of truth. The code in tensorflow/tensorflow repository IS the source of truth for the moment. Please send any PR to that. We will send announcement for the formal switch when we finish all the migration/workflow work.

We will add more documents and setup the developer workflow in the near future.

PiperOrigin-RevId: 345532569

* Replace all code with tf.keras redirects

* Added comments about the future of Keras.

* Changed msg.

* Updated readme for windows users

* Fix phrasing

* Update README.md

* Update backend.md

* Update initializers.py

* Update backend.md

### Summary
I have removed an unnecessary hyphen in "fully-configurable" to make it "fully configurable" in the README.

### Related Issues
None

### PR Overview
Fix a spelling mistake in the README.

- [n] This PR requires new unit tests [y/n] (make sure tests are included)
- [y] This PR requires to update the documentation [y/n] (make sure the docs are up-to-date)
- [y] This PR is backwards compatible [y/n]
- [n] This PR changes the current API [y/n] (all API changes need to be approved by fchollet)

* Add optional dependencies' links to download pages in README

* Update Graphviz link in README as they just changed it

* Update cuDNN link in README

* Update README.md

Made explicit HTTPS calls and change absolute link to relative link

* Update README.md

Add license link and adding absolute link

* Update REAMDE.md

Removing link to license

Remove incorrect usage of "either"

* Added Gitter channel badge

Assigned @fchollet as channel admin on Gitter

* Link fix