Resolve ALL remaining spell checking issues right before the `docs.ton.org` release

[novusnota]

For example, in some recent PRs, e.g., #596, the word "Describtion" (not "Description") was not flagged as incorrect.

This task was created when working on fixing spell checking in #616. In addition to notes here, see more notes there.

IFF it would be impossible to resolve false-positives with Vale and adjusting its .vale.ini config, we might switch to:

• Direct CSpell usage
• or remark-based spelling checks, that might be extended to further prose or Markdown lints

[novusnota]

It turns out that most of the RegExes we have are either redundant or invalid. That is, in .vale.ini, we only need this:

# import ..., export ...
TokenIgnores = '(?sm)(^(?:import|export) .+?(?=\r?\n\r?\n))'

# $$\n...\n$$
BlockIgnores = '(?sm)(?<!\\)\$\$\r?\n.*?(?<=\n)\$\$'

That said, there might be further edits necessary.

TODO to self:

• discover and apply such necessary edits
• debug Vale behavior on larger files with JSX expressions on top {}

If we won't be able to easily debug Vale for all files, we should consider switching to CSpell.