Texas Farm-to-Market (FM) routes should have FHWA Series D for route number

[Clay Smalley]

I know there may be a little bit of artistic license taken with this project, but most Texans are accustomed to seeing FHWA Series D on 99.99% of all route signs. FHWA Series B, which the project currently uses for the FM/RM routes, looks a little foreign and strange on a route sign to a Texan.

It might be a good idea to have a separate .svg for 2-digit, 3-digit, and 4-digit. They all use FHWA Series D at different font sizes. Here are some examples:

_2: https://en.wikipedia.org/w/index.php?title=File:Texas_RM_12.svg
_3: https://en.wikipedia.org/w/index.php?title=File:Texas_FM_865.svg
_4: https://en.wikipedia.org/w/index.php?title=File:Texas_FM_1093.svg

[Phil! Gold (asciiphil)]

I'll see what I can do. The Farm- and Ranch-to-Market shields are a little tricky already, because they have so much less space available to the digits relative to other shields at the same image heights (and I'm already cheating by making the FM/RM shields a little larger than everything else). I should be able to do at least the two-digit shields with a Series D font; I'll have to see how legible the rest are at the smaller font size that would require.