Changes

• You can now limit query results to a specific number of tasks (#76)
• You can now filter query results by heading (#35)
• You can now use relative dates in your query filters (#1)

This is an example of what is now possible:

```tasks
not done
due after yesterday
due before in two weeks
heading includes task
limit to 10 tasks
```

Meaning “the first ten open tasks that are due within the next two weeks (starting today (after yesterday)) and where the heading includes task (for example ## Tasks)”.

See the README for all the details.