Add links to reading material

slides/c_slides.md

@@ -598,5 +598,5 @@ struct config {
 - Your favourite C tutorial
 - Read up on common C standard library functions
 - Man-pages
-- SEI CERT C Coding Standard
+- [SEI CERT C Coding Standard](https://wiki.sei.cmu.edu/confluence/display/c/SEI+CERT+C+Coding+Standard)
 - Revisit operating system lecture on libraries

slides/git_slides.md

@@ -400,7 +400,6 @@ Fetch / Pull
 
 ## Reading Material
 
-- Bitbucket / GitHub documentation
-- Git Book
-- Your favourite Git tutorial
-- Man-pages (!)
+- [Bitbucket Git Tutorial](https://www.atlassian.com/git/tutorials)
+- [Git Book](https://git-scm.com/book)
+- Man-pages

slides/tools_slides.md

@@ -365,5 +365,5 @@ indent_size = 2
 ## Reading Material
 
 - Some GDB tutorial
-- GNU Make Manual
-- Clang-Format documentation
+- [GNU Make Manual](https://www.gnu.org/software/make/manual/make.html)
+- [Clang-Format documentation](https://clang.llvm.org/docs/ClangFormat.html)