Add aligned table tutorial

[oruebel]

• Add tutorial for AlignedDynamicTable
• Update make clean command for docs to remove files generated by sphinx-gallery
• Update docstring of AlignedDynamicTable
• Add custom thumbnails for all tutorials to ease navigation and make the gallery look nicer

Fix #570
Fix #569
Fix #572
Fix #574

Checklist

• Did you update CHANGELOG.md with your changes?
• Have you checked our Contributing document?
• Have you ensured the PR clearly describes the problem and the solution?
• Is your contribution compliant with our coding style? This can be checked running flake8 from the source directory.
• Have you checked to ensure that there aren't other open Pull Requests for the same change?
• Have you included the relevant issue number using "Fix #XXX" notation where XXX is the issue number? By including "Fix #XXX" you allow GitHub to close issue #XXX when the PR is merged.

[oruebel]

@rly I addressed the issues you raised. Can you please review the changes and approve the PR if everything looks good.

[rly]

I made minor suggestions. Otherwise looks good.

[oruebel]

@rly I added the additional changes you suggested. Can you please re-approve the PR.

[rly]

@oruebel Did you push your changes re: tests?

[oruebel]

Sorry, I didn't notice that the push had failed. I just pushed the changes.