Add warning about the repository size (>1.6Gb)

[savchenko]

Cloned while using a metered connection by mistake...

Cloning into 'difftastic'...
remote: Enumerating objects: 132198, done.
remote: Counting objects: 100% (700/700), done.
remote: Compressing objects: 100% (545/545), done.
remote: Total 132198 (delta 550), reused 197 (delta 152), pack-reused 131498 (from 3)
Receiving objects: 100% (132198/132198), 1.62 GiB | 18.83 MiB/s, done.
Resolving deltas: 100% (91227/91227), done.

[felipe-heredia]

Also warning about the binary size.

[cachius]

There goes the plan for a wasm build.

[Wilfred]

Yeah, sorry the repo is so big. All the git subtrees with checked in generated C code has massively ballooned the size. Cloning with a depth limit is much better, and I should document this.

[Wilfred]

Regarding the binary size, I think it's become too big. Previous releases were around 60 MiB so this is a big jump.

I'm guessing one of the new parsers (maybe the SQL parser which has changed?) is much bigger.

It might be time to look at dynamically loading parser libraries, and probably reduce the default set.

[Wilfred]

See also #343.