Add control pictures

[zacharie-moughanim]

The "whitespace glyph" is the symbol often used to designate the spacebar on keyboards : ␣.
I'm honestly not sure about the name, nor if it is pertinent to put it as a variant of space, which always designate whitespaces.

[MDLC01]

Note that a similar character exists in Unicode: U+2420 ␠ SYMBOL FOR SPACE. Both come from the Control Pictures block.

[Enivex]

The name in html is blank, but https://www.compart.com/en/unicode/U+2422 also exists

[zacharie-moughanim]

Maybe we could remove forget about the name space.glyph, add the name blank and group ␣, U+2420, U+2422 as variants of this name, what do you think ?

[MDLC01]

According to French Wikipédia, U+2422 ␢ is used in theoretical computer science.¹ I am struggling to find uses of this symbol other than the book mentioned on this page, and unable to locate the proposal that lead to its inclusion to Unicode. I do not know whether we actually want to assign it a name.

My intuition is that the graphic pictures for control codes (i.e., 2400..2421 and 2424) should be in their own sub-module because they are so clearly related without being variants of each others. Then, U+2423 ␣ could either be a variant of U+2420 ␠ and U+2422 ␢ sym.blank, or U+2423 ␣ could be its own symbol outside of the sub-module but that causes a potential collision if we want to include U+2422 ␢ as well.

Footnotes

1. https://fr.wikipedia.org/wiki/%C9%83#Symbole_blanc ↩

[MDLC01]

Also, don't forget to update the changelog to mention the addition(s).

[zacharie-moughanim]

Just added each symbol representing a non-printable character under a submodule control :

␀ // symbol for null
␁ // symbol for start of heading
␂ // symbol for start of text
␃ // symbol for end of text
␄ // symbol for end of transmission
␗ // symbol for end of transmission block
␅ // symbol for enquiry
␇ // symbol for bell
␇ // symbol for backspace
␉ // symbol for horizontal tabulation
␋ // symbol for vertical tabulation
␊ // symbol for line feed
␌ // symbol for form feed
␍ // symbol for carriage return
␎ // symbol for shift out
␏ // symbol for shift in
␐ // symbol for datalink escape
␑ // symbol for device control one
␒ // symbol for device control two
␓ // symbol for device control three
␔ // symbol for device control four
␆ // symbol for acknowledge
␕ // symbol for negative acknowledge
␖ // symbol for synchronous idle
␘ // symbol for cancel
␙ // symbol for end of medium
␚ // symbol for substitute
␦ // symbol for substitute form two
␛ // symbol for escape
␜ // symbol for file separator
␝ // symbol for group separator
␞ // symbol for record separator
␟ // symbol for unit separator
␠ // symbol for space
␡ // symbol for delete
␥ // symbol for delete form two
␢ // blank symbol
␣ // open box
␤ // symbol for newline

I got most of the names from compart and from this wikipedia page.

[Enivex]

I think we should use the full words acknowledge, substitute, synchronous, escape, and delete

Edit: Missed a couple

[zacharie-moughanim]

I think we should use the full words acknowledge, substitute, synchronous, escape, and delete

Edit: Missed a couple

Done

[MDLC01]

For the control code pictures, I am wondering whether it would actually be better to use the common abbreviations for the symbols (e.g., as listed at https://en.wikipedia.org/wiki/Basic_Latin_(Unicode_block)#Table_of_characters), which seems to match the letters displayed on the corresponding glyphs?

Right now, multiple variants feel weird, such as heading.start or transmission.end, because they seem to imply the existence of a dual variant (heading.end and transmission.start) that does not in fact exist (or rather, it exists under a different name: heading.end is text.start and transmission.start is heading.start). I feel like most control codes exist as is and aren't variants of each others, so using separate names would make more sense.

[T0mstone]

I have to say I don't like this breaking words into modifiers just for the sake of it, especially when there's no meaningful default variant.

[zacharie-moughanim]

Replaced each name from the control submodule to abbreviations.
Therefore, I only left the abbreviations in this submodule.
I put the two symbols that are used as keyboard labels out of the module, under the names spacebar for ␣ and delete for ␥.
Two symbols from the control pictures block remains : ␦ and ␢, but they seemingly does not fit within the control submodule, and are not used in keyboard labels, so I left them out of this pr.

[zacharie-moughanim]

Also, there are four symbols whose name is not the exact abbreviations, device controls (1, 2, 3, 4) since apparently numbers aren't allowed in symbol names.
I looked at the name for dice, so I named them dc.one ␑, dc.two ␒, dc.three ␓, dc.four ␔.
The default is dc.one which is arbitrary. Tell me if there is a better way to name them.