* add to documentation

* Added RPi cheatsheets

* Update free-programming-cheatsheets.md

* Update free-programming-cheatsheets.md

* Update free-programming-cheatsheets.md

* Update free-programming-cheatsheets.md

* Update free-programming-cheatsheets.md

fixed 404 broken link issue

* Update free-programming-cheatsheets.md

* Update CONTRIBUTING.md

* Added Blockchain books -PDF

* Delete free-programming-books-langs.md

* Re-added books

* Additional changes, mods.

* Update free-programming-books-langs.md

* Modifications contrib.

* Update CONTRIBUTING.md

* Update CONTRIBUTING.md

* Additions for Tensorflow cheatsheets (other branch)

* Update free-programming-cheatsheets.md

* Changes on other files

* Update free-programming-cheatsheets.md

* Additional changes

* Final changes for cheatsheets page nl ends.

* Update free-programming-cheatsheets.md

added the official content from kaggle for TF (includes pdf link, html only)
removed the blog TF link at the top (as per contributing.md guidelines)

* Update free-programming-books-langs.md

About: Blockchain additions, removed all the whitepapers from the list.

Why is the "Introducting Eth*" allowed in the PDF list of ebooks and the "*for dummies" series  not allowed? I do not see that rule in the contributing.md file
AFAIK, both are online ebooks links, both with an ISBN/Table Of Contents for chapters.

Either way, i replaced the first one with one that is free from offic. ibm public link

* delete patch

* Remove patch. not free
Co-authored-by: NDavid Ordás <3125580+davorpa@users.noreply.github.com>

* use wayback machine to provide its backed PDF link
Co-authored-by: NDavid Ordás <3125580+davorpa@users.noreply.github.com>

* add in process, creator
Co-authored-by: NDavid Ordás <3125580+davorpa@users.noreply.github.com>

* blockchain is not a language. the dummies book should be is subjects list
Co-authored-by: Neric <eric@hellman.net>
Co-authored-by: NDavid Ordás <3125580+davorpa@users.noreply.github.com>