build: remove compile_mjml script, no python!

if I had taken a second to actually read the documentation, i'd have
    realized the mjml command can process a bunch of files at once.
    On my machine, cuts time down from ~800ms to ~500ms.
While there are still some scripts using python, none are needed to
build the software anymore, so no python build deps!

config/README.md

@@ -1,4 +0,0 @@
-###  fixconfig
-
-Python's `json` library retains the order of data in a JSON file, which meant settings sent to the web page would be in the right order. Go's `encoding/json` and maps do not retain order, so `enumerate/enumerate_config.py` opens the json file, and for each section, adds an "order" array which tells the web page in which order to display settings. 
-Specify the input and output files with `-i` and `-o` respectively.

config/README.txt

@@ -0,0 +1 @@
+The two python scripts here, `config-json-to-new-yaml.py` and `gen-rough-schema.py` were used to convert the old format, which was stored in a JSON file, to the new format in YAML. The latter script is used to get the possible values for settings and sections, so they could be properly defined in common/config.go.