Add highlighting for Igor Pro procedures

[t-b]

Available in pygments since 5ceb7533e214.
For a background of IGOR Pro see www.wavemetrics.com and www.igorexchange.com.

Repositories with igor procedure files:

• https://github.com/stakahama/igorlib
• https://github.com/yamad/igorutils
• https://github.com/dleifohcs/srs-igor
• https://github.com/david-hoffman/Igor-Data-Analysis
• https://github.com/bmcguyer/DAQ_Procedures_for_Igor_Pro

Pygments has a special style for igor pro. Is there a way I can force a specific pygments style?

pygmentize -L styles | grep -A1 igor
* igor:
    Pygments version of the official colors for Igor Pro procedures.

[t-b]

Is there anything I can do to bring this PR to the next step?

[pchaigno]

You could remove samples.json from the PR, it would ease the merge process. (Because it's a generated file and #1316 is not merged yet, it creates merge conflicts.)

[t-b]

@pchaigno Thanks for the quick answer. I removed samples.json, rebased against master, made some minor corrections and force pushed.

[pchaigno]

Ok, seems good. You just have to wait now.