Feature request: Add more contextual alternates

[mjwsteenbergen]

Right now, this font supports the -> to 🡒 ligature. This means that when typing ->, you see 🡒. It would be awesome if more of these ligatures are implemented. An example of ligatures is shown below:

[rsms]

Some of these conversions are risky in terms of opinion/expectation. I.e. I might actually want to type "!=" rather than "≠" which should be possible. Since contextual alternates and contextual ligatures are enabled by default (i.e. in macOS, Windows, FreeType and Harfbuzz) it would be best to pursue this as discretionary ligatures (dlig).