Expand the documentation for createTempFileName and add withTempFileName

Add `createTempFileName` helper.

Update stack.yaml

Release temporary-1.3

createTempDirectory: generate random (not sequential) directory names

Release 1.2.1.1

s/the/a/

Make the docs more consistent

Document file/directory templates and their semantics.

Add a note about the transformers dependency

Release v1.2.1

Update copyright/authorship information and move it to LICENSE

Fix tests on earlier GHCs

Test that withTempDirectory deletes the directory

Document that the action may remove the temp file