[MISC] Fixing Travis errors with Remark

[franklin-feingold]

Addresses a common error we see with Travis flagging files because of style issues. Added a short tutorial of how to use Remark to fix this error

[sappelhoff]

very sensible to include this, thanks @franklin-feingold

[effigies]

Overall looks good. Some suggestions.

[effigies]

Suggesting a code block doesn't work well, so just using straight markdown below:

---

If it passes, replace flagged_file.md with the contents of flagged_file_fixed.md,
add and commit the change:

mv flagged_file_fixed.md flagged_file.md
git add flagged_file.md
git commit -m 'STY: Fixed Markdown style'

[effigies]

Is this a worry?

[franklin-feingold]

shouldn't the files be named the same so it gets updated properly? we don't want the bad and fixed next to each other

[effigies]

Right, it just seems a bit obvious. Whatever, though.

[effigies]

I think I was unclear with shell terminology, so I've suggested an updated section 2. Can you also update .travis.yml:

bids-specification/.travis.yml

Line 8 in 3380de8

- npm install remark-cli@5.0.0 remark-lint@6.0.2 remark-preset-lint-recommended@3.0.2 remark-preset-lint-markdown-style-guide@2.1.2

[effigies]

Oh man, I wrote the comment and forgot to hit "Start a review", so I lost it. I checked, and we can use back-ticks on Bourne-compatible shells (i.e., sh, bash, dash, zsh) as well as csh and ksh, which makes up probably 99.9% of Unix shells.

Here's the suggested update to section 2:

---

2. Install Remark-CLI and our style guide

Remark-CLI can be installed via npm, which is part of
the NodeJS distribution.

To install the packages we use for our style guide, the following command will
work on most command lines:

npm install `cat npm-requirements.txt`

The equivalent command on PowerShell is:

npm install @(cat npm-requirements.txt)

[franklin-feingold]

updated with your suggestion and updated travis. Thank you

[effigies]

Thanks for your patience

[sappelhoff]

Thanks Franklin!