Adding Handbooks (#6482)

* Adding Handbooks

* Update free-programming-books-langs.md

books/free-programming-books-langs.md

@@ -1335,6 +1335,7 @@ That section got so big, we decided to split it into its own file, the [BY SUBJE
 #### Svelte
 
 * [Svelte Tutorial](https://svelte.dev/tutorial/basics) - Svelte.dev
+* [The Svelte Handbook](https://flaviocopes.com/page/svelte-handbook/) - Flavio Copes (PDF, EPUB, Kindle) *(email address requested)*
 
 
 #### Vue.js
@@ -1428,6 +1429,7 @@ That section got so big, we decided to split it into its own file, the [BY SUBJE
 * [Ten Steps to Linux Survival: Bash for Windows People](http://dullroar.com/book/TenStepsToLinuxSurvival.html) - Jim Lehmer
 * [The Debian Administrator's Handbook](https://debian-handbook.info)
 * [The Linux Command Line](http://linuxcommand.org/tlcl.php) (PDF)
+* [The Linux Commands Handbook](https://flaviocopes.com/page/linux-commands-handbook/) - Flavio Copes (PDF, EPUB, Kindle) *(email address requested)*
 * [The Linux Development Platform](http://ptgmedia.pearsoncmg.com/imprint_downloads/informit/perens/0130091154.pdf) (PDF)
 * [The Linux Kernel Module Programming Guide](https://sysprog21.github.io/lkmpg/)
 * [The Linux System Administrator's Guide](http://www.tldp.org/LDP/sag/html/index.html)