new working link for the same pdf and new book from same source about the same subject (#6851)

* new working link for the same pdf

* update in md and added new book

books/free-programming-books-no.md

@@ -5,4 +5,5 @@
 
 #### Latex
 
-[LATEX for nybegynnere](http://dag.at.ifi.uio.no/public/doc/latex-for-nybegynnere.pdf) - Dag Langmyhr (PDF)
+* [LaTeX for nybegynnere](https://www.mn.uio.no/ifi/tjenester/it/hjelp/latex/latex-for-nybegynnere.pdf) - Dag Langmyhr (PDF)
+* [LaTeX for viderekomne](https://www.mn.uio.no/ifi/tjenester/it/hjelp/latex/latex-videre.pdf) - Dag Langmyhr (PDF)