feat(Profpatsch/netencode): add netencode-mustache

A little executable, combining the netencode and mustache libraries to
make easy templating from the command line possible.

Combined with the nix netencode generators, it’s now trivial to
populate a mustache template with (nearly) arbitrary data.

Yay.

Change-Id: I5b892c38fbc33dd826a26174dd9567f0b72e6322
Reviewed-on: https://cl.tvl.fyi/c/depot/+/2320
Reviewed-by: Profpatsch <mail@profpatsch.de>
Tested-by: BuildkiteCI

users/Profpatsch/netencode/netencode.rs

@@ -338,7 +338,7 @@ pub mod parse {
         ))(s)
     }
 
-    fn t_t(s: &[u8]) -> IResult<&[u8], T>  {
+    pub fn t_t(s: &[u8]) -> IResult<&[u8], T>  {
         alt((
             text,
             binary(),