Updates AMS to V5

[eliocamp]

Following #298. I wanted to push this only after submitting and being given the A-OK from the good people at the AMS. But now it turns out I won't be submitting to that journal, so, well, here's the updated version of the AMS article template.

[CLAassistant]

All committers have signed the CLA.

[cderv]

Thanks @eliocamp ! I see there is hook you mentioned in #298. Is this a modified version of knitr::hook_plot_tex() ?

@yufree, as the original contributor, do you want to take a look at this too ?

[eliocamp]

Thanks @eliocamp ! I see there is hook you mentioned in #298. Is this a modified version of knitr::hook_plot_tex() ?

Yep. The change is that it uses appendcaption instead of caption. Is part of the instructions from the AMS template.

[yufree]

It seems the check could not pass:

! Package inputenc Error: Unicode character ≤ (U+2264)

  (inputenc)                not set up for use with LaTeX.

To solve this issue, you could change the latex engine from pdflatex to xelatex in the template to avoid the issue.

[eliocamp]

I added xelatex as latex_engine in the skeleton.

[yihui]

Yep. The change is that it uses appendcaption instead of caption. Is part of the instructions from the AMS template.

@eliocamp If you had to copy the 150 lines of code of hook_plot_tex from knitr, modify one line, and add to this package, I'll definitely reconsider https://github.com/yihui/knitr/issues/1872, because otherwise this will be a disaster for us to maintain in rticles :)

[cderv]

Sorry for the delay. V6 template for AMS is out. Should we consider V6 and abandon V5 here ? https://github.com/rstudio/rticles/issues/298#issuecomment-914373266

[cderv]

I am closing this PR in favor of #444.

Thanks.