Preventing Jekyll from running liquid on imported content

[furnstahl]

When we read in bandsdk.md or other content from bandframework (or elsewhere), the imported content by default is rendered by liquid. This will cause a problem if there is syntax imported that is misinterpreted by liquid. This happened with markdown in bandsdk.md that used {{ in a BibTeX entry, which threw a liquid error. This has been fixed by changing {{ --> { { in that file, but a better solution would be to suppress the rendering when the file is included.

Note that one rendering problem was fixed by renaming _pages/submodules to _pages/_submodules, which tells liquid to not render all the files in _submodules (which it was doing).

But so far there is not a working fix for being able to do an include like:
{% include_relative _submodules/bandframework/resources/sdkpolicies/bandsdk.md %}
and keep it from being rendered by liquid. Attempts to use raw/endraw and capture/endcapture did not succeed.