fix issue #38 by using relLangURL to generate href's

[ranger6]

One line change as described in issue #38

Tested with hugo server.

To test:

1. Clone https://github.com/ranger6/noteworthy-example and checkout the issue38 branch. This branch points to the issue38 branch of the noteworthy theme submodule: https://github.com/ranger6/hugo-theme-noteworthy
2. Initialize the submodule
3. Run hugo server or generate the site and publish

N.B. the baseURL in this example points to a GitHub pages site: https://ranger6.github.io/noteworthy-example/ This site currently contains the example with the bug present (e.g. published from the master branches, not the fix branch).