doc: Mention needed bash version

[why]
Some bash scripts we have need bash version 4 or better. For example native
arrays where added with that version in 2009.

Unfortunately Apple decided to keep a very very old version of bash in
their setup which will not work.

[how]
Add information on needed bash version at least in the readme file.

We could now rewrite all scripts to work with bash 3; I tried that but that
is a tremendous amount of work and I guess the time is spent better on some
real problems; especially because only a small number of users are affected
and they could also just switch to recent bash version.

We could also add checks for the bash version to the scripts. This is not
done here.

[note]
Also remove obsolete explanatory entry; that subdir has been deleted.

Fixes: #1680

Signed-off-by: Fini Jastrow <[email protected]>

bin/scripts/README.md

@@ -2,6 +2,9 @@
 
 Note: Usually you need to call the scripts in this directory while actually being in this directory (i.e. `pwd = .../nerd-fonts/bin/scripts`).
 
+Shell scripts here require a halfway recent version of `bash`, i.e. at least version 4 which came out in 2009.<br />
+MacOS usually has a `bash` version 3; you can install a current version via Homebrew.
+
 * `archive-font-patcher.sh`: Archives the font patcher script and subscripts and the required source glyph files [1]
 * `archive-fonts.sh`: Creates the release zip file of one or more font(s) from existing `patched-fonts/` content [1]
 * `cheatsheet.sh`: Search for a glyph by part of its name [4]
@@ -22,7 +25,6 @@ Note: Usually you need to call the scripts in this directory while actually bein
 * `generate-webfonts.sh`: Generate woff and woff2 font files from the SymbolsOnly font (for the gh-pages) [1]
 * `get-font-names-from-json.sh`: Helper to setup the CI font matrix from `data/fonts.json` [1]
 * `gotta-patch-em-all-font-patcher!.sh`: Patch one or more fonts 'complete' with and without `mono` and with and without `windows compat` [1]
-* `Hack/`: Special additional post patching script for Hack, invoked via Hack's `config.cfg` (not used when self-patching)
 * `lib/`: See its own README
 * `name_parser/`: Suite to set up sane Family and SubFamily names, used by `font-patcher` (on demand)
 * `optimize-original-source.sh`: Run all icons in `src/svgs` through inkscape to simplify (remove nodes and edges) [5]