Some code to make Fira Code 2.0 work in Emacs.
To install, first run make. Copy some or all of the files in
modified to you ~/.fonts directory. Put fira-code.el and
fira-code-data.el into your load-path, and ensure fira-code-mode
is enabled for any buffers where you want ligatures. Set your default
font to one of the Fira Emacs variants. If you want to see all the
ligatures variant characters, open fira-code-data.el in Emacs.
To control which ligatures and alternative characters are used, set
fira-code-enable-substitution-predicate and
fira-code-compose-predicate. Refer to the default values for an
example of how to write your own predicates.