feat: allow special and lower-cased characters

[raphamorim]

Special Characters

This PR fixes:

• Non-alphabetic control characters are missing syntax highlighting #4

cat > vhs.tape
Ctrl+\

vhs vhs.tape
File: vhs.tape
  1 │ Ctrl+\
          ^ Not a valid modifier

  1 │ Ctrl+\
          ^ Invalid control argument: +

  1 │ Ctrl+\
           ^ Expected control character with args, got \

parser: 3 error(s)
recording failed

Lower-cased Characters

This allow VHS to support/highlight lowercased characters on Ctrl/Alt/Shift

====
Case sensitive on Ctrl/Alt/Shift
====

Ctrl+A
Ctrl+a
Alt+B
Alt+b
Shift+C
Shift+c

---

(program
 (command (control))
 (command (control))
 (command (alt))
 (command (alt))
 (command (shift))
 (command (shift)))

Nowadays we treat it on VHS and it does work with lower-cased however the syntax doesn't match

[caarlos0]

lgtm, but will need changes in vhs as well

[andreynering]

Missing final line break.

[raphamorim]

oh actually that was made by editorconfig plugin, is the rule without or with linebreak @caarlos0 @aymanbagabas @bashbunni ?

[raphamorim]

oh actually that was made by editorconfig plugin,

that's using the root editorconfig