Expand on the “ligatures” section

[mostafah]

Our ligatures section (currently numbered as 2.4.2) only talks about lam and alef ligatures. It should cover other ligatures as well.

Also, this is the last sentence of the section:

Each of these ligatures also provides a special shape for joining from its right side (to the preceding letter).

It is talking about variations of the lam and alef ligature, but that’s not clear enough and it can confuse readers into thinking that all ligatures are right-joining only.