Change dead Bitbucket links to Sourcehut.

The arduino-pn532 repo wiki was not transferred
to Sourcehut and therefore is gone forever. Links
to the now dead wiki have been marked as broken.
Add software I2C article.
Add software I2C example.
Add Fedora 25 rpms article.
Add license headers (ISC license).
Add link to examples.
Add Trinket article.
Add rpi1 package article.
Add UE/UES template file for rst files.
Development version of content generation bash script.
Initial draft of traffic lights article.
Add css style for pre tag.
Add summary and feed_summary plugins.
Remove 404 page.
Add Disqus update.
Add another PN532 article.

I2C, NXP Mifare Classic, Yubikey NEO.
Add new .hex files for PN532/NFC.
Disable disqus.

Not that many comments and if you want to comment
the article, you can use,,
Twitter, or email.

As a bonus, less 3rd tracking.
Use local jquery file.
Ignore .bak and .pyc files and output/ directory.