Write README

README.md

@@ -0,0 +1,42 @@
+# Rotagen
+
+Rotagen is a simple, configurable rota generator program.  The people
+available, jobs that need doing, slots available for doing jobs and
+constraints/exceptions (such as someone not being available for a
+particular slot or being unable to do a certain job) are specified in
+a config file in an ini-like format.
+
+## Building
+
+The tool is written in C99 and has no dependencies other than the C
+standard library.  A Makefile is provided to build the executable on
+POSIX systems; to use it to build a binary simply run `make` from the
+root of the repository.
+
+## Running
+
+The tool must have a configuration file to run.  The file's path can
+be specified in the first command-line argument, or will default to
+"rotagen.conf" in the working directory if unspecified.  For example,
+if your config file was at the path "~/foo.conf", you would run
+`rotagen ~/foo.conf`.  There is an example configuration in
+`example.conf`; refer to this for the configuration file syntax.
+
+## Bugs / Limitations
+
+- The tool will hang indefinitely if it is unable to find a rota that
+  satisfies the constraints.
+- If someone is exempted from a slot or job due to a contraint this
+  does not affect the probability they will be allocated to other
+  slots or jobs so the generated rotas are slightly unfair.
+- The behaviour of ensuring someone is not allocated for two
+  consecutive slots is not configurable, it should be specifiable as a
+  constraint in the config file
+- The only types of contraint that are supported are slot or job
+  exemptions
+
+## License
+
+Rotagen is available under the GNU Affero General Public License,
+version 3, see the `LICENSE` file for details.  Contributions are very
+welcome and no contributor license agreement is required.