Add logbook

Logbook.md

+# Log Book for this MOOC
+**Description:**
+Add all information that I might useful, as well as how much time I spent on
+the modules, for example. 
+
+## Time spent on Module
+09.11 = 2 hours
+10.11 = 2:30 hours
+
+
+## Useful programs
+- DocFetcher for looking for keywords in a large number of documents
+- Exiftool for adding metadata to pictures and PDFs
\ No newline at end of file