Add a rudimentary README

Author: mgedmin

README.md

@@ -0,0 +1,20 @@
+svn-all-fast-export aka svn2git
+===============================
+
+This is the tool used to convert KDE's Subversion into multiple Git
+repositories.  You can find more description and usage examples at
+https://techbase.kde.org/Projects/MoveToGit/UsingSvn2Git
+
+
+Building
+--------
+
+Run `qmake && make`.  You get `./svn-all-fast-export`.
+
+
+Usage
+-----
+
+You need to write a rules file that describes how to slice the Subversion
+history into Git repositories and branches.  See
+https://techbase.kde.org/Projects/MoveToGit/UsingSvn2Git.