doc: Style and consistency in user/index.
doc: Fix ssh-access typos and consistency.
doc: Fix api-tokens typos and consistency.
doc: Fix tutorial-keep typos and consistency.
doc: tutorial-pipeline-workbench style+clarity.
doc: tutorial-firstscript style consistency.

Conflicts:
	doc/user/tutorials/tutorial-firstscript.html.textile.liquid
doc: tutorial-new-pipeline clarity.

I renamed the "filter" job to "do_filter" to help disambiguate it a
little from "0-filter.py".

Conflicts:
	doc/user/tutorials/tutorial-new-pipeline.html.textile.liquid
doc: Tweak running-external-program style.
doc: Use $USER in tutorial JSON.

The tutorial encourages users to copy and paste command text.
However, most of the JSON needs to have a user-specific value for
"repository", which is easy to overlook.  Since we're telling users to
save JSON with @cat@, we can take advantage of shell variable
expansion to make the right thing happen automatically.

I added accompanying notes to help explain what's going on for people
who aren't copying instructions so literally.

Conflicts:
	doc/user/tutorials/tutorial-firstscript.html.textile.liquid
	doc/user/tutorials/tutorial-new-pipeline.html.textile.liquid
doc: Highlight "you" in reference JSON.

Since this reference provides users with raw example JSON, and doesn't
tell them to write it with @cat@, we can't rely on shell variable
expansion here.
doc: Make running-pipeline-command up-to-date.

* @arv pipeline run@ now requires @--run-here@.
* Pipelines are now under Activity in Workbench navigation.
* The format of the example output has changed, along with all the
  Keep hashes.
doc: tutorial-job-debug update and style.

* Jobs now require a "repository" parameter.
* Use environment variables to specify the job script.
doc: Fix typos in tutorial-parallel.
doc: Keep topic style tweaks.
doc: job-and-pipeline-ref grammar fixes.
doc: tutorial-job1 updates and style tweaks.

The major change here is that we set no_reuse on the job, to avoid
confusing people by using results from previous tutorial runs.  These
updates also reflect some minor changes in the Workbench UI.
doc: Implement Tom's suggested improvements.

Refs #2470.
doc: Style and consistency in user/index.
doc: Fix ssh-access typos and consistency.
doc: Fix api-tokens typos and consistency.