Added section headings to README.md.

README.md

@@ -21,6 +21,9 @@ PyQSO
 
 PyQSO is a general-purpose contact logging tool for amateur radio operators.
 
+Installation and running
+------------------------
+
 Assuming that the current working directory is PyQSO's base directory (the directory that the Makefile is in), PyQSO can be installed via the terminal with the following command:
 
    `make install`
@@ -35,6 +38,9 @@ Alternatively, PyQSO can be run with:
 
 from PyQSO's base directory.
 
+Documentation
+-------------
+
 The PyQSO user manual is stored as a LaTeX source file in the doc/ directory. It can be compiled with the following command:
 
    `make manual`