docs: transfer links for cheatsheets from books page to new cheatsheets page and add css/js cheatsheets (#4557)

* docs: add links for cheatsheets

* docs: remove links for cheatsheets from books page

free-programming-books.md

@@ -245,8 +245,6 @@
 * [Bento](https://www.bento.io)
 * [Bitsavers.org](http://bitsavers.trailing-edge.com)
 * [Bookboon: IT & Programming](http://bookboon.com/en/it-programming-ebooks) Cookie required. (email address *requested*, not required)
-* [Cheat Sheets (Free)](https://dzone.com/refcardz)
-* [Cheat Sheets for Data Scientists](https://www.datacamp.com/community/data-science-cheatsheets) - Datacamp (PDF)
 * [conceptf1.blogspot.com](http://conceptf1.blogspot.com/2013/11/list-of-freely-available-programming.html)
 * [Free Smalltalk Books, collected by Stéphane Ducasse](http://stephane.ducasse.free.fr/FreeBooks.html)
 * [Free Tech Books](http://www.freetechbooks.com)
@@ -1128,7 +1126,6 @@ Kerridge (PDF) (email address *requested*, not required)
 * [A Brief Beginner’s Guide To Clojure](http://www.unexpected-vortices.com/clojure/brief-beginners-guide/)
 * [Clojure - Functional Programming for the JVM](http://java.ociweb.com/mark/clojure/article.html) - R. Mark Volkmann
 * [Clojure by Example](https://kimh.github.io/clojure-by-example/) - Hirokuni Kim
-* [Clojure Cheat Sheet](http://clojure.org/cheatsheet)
 * [Clojure community-driven documentation](http://clojure-doc.org)
 * [Clojure Cookbook](https://github.com/clojure-cookbook/clojure-cookbook)
 * [Clojure Distilled Beginner Guide](http://yogthos.github.io/ClojureDistilled.html)
@@ -1367,7 +1364,6 @@ Kerridge (PDF) (email address *requested*, not required)
 * [Git Reference](https://web.archive.org/web/20170602211147/http://gitref.org/)
 * [Git Succinctly, Syncfusion](https://www.syncfusion.com/resources/techportal/ebooks/git) (PDF, Kindle) (email address *requested*, not required)
 * [Git Workflows](http://documentup.com/skwp/git-workflows-book)
-* [GitHub Cheat Sheet](https://github.com/tiimgreen/github-cheat-sheet) - Tim Green (Markdown)
 * [How to Collaborate on Github](https://github.com/eonist/How-to-collaborate-on-github) - André J
 * [Intoduction to Git and Github](https://launchschool.com/books/git) - Launch School
 * [Intoduction to Git and Github - Tutorial](http://cse.unl.edu/~cbourke/gitTutorial.pdf) - Dr. Chris Bourke (PDF)
@@ -1835,7 +1831,6 @@ Kerridge (PDF) (email address *requested*, not required)
 
 * [Learning Vue.js](https://riptutorial.com/Download/vue-js.pdf) (PDF)
 * [The Vue.js Handbook](https://flaviocopes.nyc3.digitaloceanspaces.com/vue-handbook/vue-handbook.pdf) - Flavio Copes (PDF)
-* [Vue Essential Cheatsheet](https://www.vuemastery.com/pdf/Vue-Essentials-Cheat-Sheet.pdf) (PDF)
 
 
 ### Jenkins
@@ -1964,7 +1959,6 @@ Kerridge (PDF) (email address *requested*, not required)
 ### Markdown
 
 * [Learn Markdown](https://www.gitbook.com/book/gitbookio/markdown/details) - Sammy P., Aaron O. (PDF) (EPUB) (MOBI)
-* [Markdown Here](https://github.com/adam-p/markdown-here/wiki/Markdown-Cheatsheet) - Adam Pritchard
 
 
 ### Mathematica
@@ -2290,7 +2284,6 @@ Kerridge (PDF) (email address *requested*, not required)
 * [Code Like a Pythonista: Idiomatic Python](https://web.archive.org/web/20180411011411/http://python.net/~goodger/projects/pycon/2007/idiomatic/handout.html) - David Goodger
 * [CodeCademy Python](https://www.codecademy.com/learn/python)
 * [Composing Programs](http://composingprograms.com) (3.x)
-* [Comprehensive Python Cheatsheet](https://gto76.github.io/python-cheatsheet) - Jure Šorn (HTML) (3.7)
 * [Cracking Codes with Python](http://inventwithpython.com/cracking/) - Al Sweigart
 * [Data Structures and Algorithms in Python](https://web.archive.org/web/20161016153130/http://www.brpreiss.com/books/opus7/html/book.html) - B. R. Preiss (PDF)
 * [Dive into Python 3](https://diveintopython3.problemsolving.io) - Mark Pilgrim (3.0)

free-programming-cheatsheets-en.md

@@ -1,9 +0,0 @@
-### Index
-
-* [HTML / CSS](#html--css)
-
-
-### HTML / CSS
-
-* [CSS Flexbox Cheatsheet](https://css-tricks.com/snippets/css/a-guide-to-flexbox/) - Chris Coyier on CSS-Tricks (HTML)
-

free-programming-cheatsheets.md

@@ -0,0 +1,52 @@
+### Index
+
+* [Clojure](#clojure)
+* [Data Science](#data-science)
+* [Git](#git)
+* [HTML / CSS](#html--css)
+* [JavaScript](#javascript)
+  * [Vue.js](#vuejs)
+* [Markdown](#markdown)
+* [Python](#python)
+
+
+### Clojure
+
+* [Clojure Cheatsheet](http://clojure.org/cheatsheet)
+
+
+### Data Science
+
+* [Cheatsheets for Data Scientists](https://www.datacamp.com/community/data-science-cheatsheets) - Datacamp (PDF)
+
+
+### Git
+
+* [GitHub Cheat Sheet](https://github.com/tiimgreen/github-cheat-sheet) - Tim Green (Markdown)
+
+
+### HTML / CSS
+
+* [CSS Flexbox Cheatsheet](https://css-tricks.com/snippets/css/a-guide-to-flexbox/) - Chris Coyier (HTML)
+* [CSS Grid Cheatsheet](https://css-tricks.com/snippets/css/complete-guide-grid/) - Chris House (HTML)
+
+
+### JavaScript
+
+* [JavaScript Cheatsheet](https://www.codecademy.com/learn/introduction-to-javascript/modules/learn-javascript-introduction/cheatsheet) - Codecademy (HTML)
+
+
+#### Vue.js
+
+* [Vue Essential Cheatsheet](https://www.vuemastery.com/pdf/Vue-Essentials-Cheat-Sheet.pdf) - Vue Mastery (PDF)
+
+
+### Markdown
+
+* [Markdown Here](https://github.com/adam-p/markdown-here/wiki/Markdown-Cheatsheet) - Adam Pritchard
+
+
+### Python
+
+* [Comprehensive Python Cheatsheet](https://gto76.github.io/python-cheatsheet) - Jure Šorn (HTML)
+