[text define] - document known editor issues with escaped `,`/`;`

[ben-wes]

the editor of [text define] can't correctly handle input with escaped , and ;.

this caused me to create https://github.com/pure-data/pure-data/issues/2354 - assuming that the data itself was falsely interpreted. that's not the case though luckily (it's "only" and error in the editor, not the data).

imho, it would be good to add this information to the help of [text define] as "known issue".

there is an issue addressing this: https://github.com/pure-data/pure-data/issues/1951 ... but while this is not solved yet, it might help other users to have it documented.

some parts of the slightly irritating [text] editor behaviour are also described here: https://github.com/pure-data/pure-data/issues/1262#issuecomment-776297842

[porres]

isn't it related to https://github.com/pure-data/pure-data/issues/1600 ?

[porres]

anyway, I think it makes better sense to work on fixing bugs rather than document them

[porres]

another related issue? (I knew I reported something about this) https://github.com/pure-data/pure-data/issues/1075