- Update to version 0.054. Changes documented since 0.051 -> 0.054:
* added retro computing symbols: U+2427 ... U+2429, U+1CC00 ... U+1CEAF These
will be introduced in Unicode v16 this year, they might need
modifying once more information appears...
* added supplemental arrows U+1F8B2 ... U+1F8C1
* added: ss17 replaces Braille Characters with the equivalent Octants (U+1CD00
... U+1CDE5). It's been suggested that octants might be better than
Braille glyphs for more detailed graphics (eg see UnicodePlots), but
this ss doesn't confirm this.
* changed: Germandbls U+1E9E design improved
* changed: box drawing characters tweaked
* changed: arrows at U+21c4
* added: improved support for Hebrew (U+0591 -> U+05F4)
* added: numbers now accept non-spacing marks (such as a dot U+0307 or a hat U+0302) #196
* added: U+FFFC (fontbakery.com told me I should add it)
* added: combining diacriticals U+0305, U+0332, U+0333, U+0336, U+033F
now extend across the full width of the glyph, as per Unicode spec
* removed: soft hyphen (U+00AD) - fontbakery.com told me to remove it
*  (U+F35D) Private Use Area: external link icon:
this popular icon never quite made it into Unicode (proposal
[here](https://www.unicode.org/L2/L2018/18303-external-link.pdf)) but
it's useful.
* added mirrored versions of the non-mirrorable glyphs for BiDi (ie
right-to-left): ⅀, ∁, ∂, ∃, ∄, ∑, ∖, √, ∛, ∜, ∝, ∦,
∫, ∬, ∭, ∮, ∯, ∰, ∱, ∲, ∳, ∹, ∻, ∾, ∿, ≀, ≁,
≂, ≄, ≆, ≇, ≈, ≉, ≊, ≋, ≟, ≠, ≢, ⊌, ⊧, ⊪, ⊬,
⊭, ⊮, ⊯, ⊾, ⊿, ⋵, ⋸, ⋹, ⋿, ⌠, ⌡, ⟀, ⟌, ⟓, ⟔,
⦜, ⦝, ⦞, ⦟, ⦢, ⦦, ⦧, ⧂, ⧃, ⧉, ⧎, ⧜, ⧡, ⧣, ⧤,
⧥, ⧴, ⧶, ⧷, ⨊, ⨋, ⨌, ⨍, ⨎, ⨏, ⨐, ⨑, ⨒, ⨓, ⨔,
⨕, ⨖, ⨗, ⨘, ⨙, ⨚, ⨛, ⨜, ⨞, ⨟, ⨠, ⨡, ⨤, ⨦, ⨩,