fix: residual space after section causes bad parsing

[Nautigsam]

Any character left on a line after a section should be ignored.

If we try to parse this input :

; there is a space character left at the end of the next line
[section] 
key=value

I get the following result:

{
  "[section]": true
  key: "value"
}

Instead, I want the section to be correctly parsed.

[Nautigsam]

🆙 I rebased the PR on main branch.

[wraithgar]

Rebased in #203 to let CI run