linting: fix typos, add toml validation (#7007)

- adds the `toml` plugin to the `eslint` linting → expect to have `options/setting/config.toml` by #6862
- fixes `make lint-codespell` commands
- related concerning `codespell`: #3270
- info: codespell check is and was not activated in the workflows (could maybe, runs only few seconds on my system)

Reviewed-on: https://codeberg.org/forgejo/forgejo/pulls/7007
Reviewed-by: Earl Warren <earl-warren@noreply.codeberg.org>
Co-authored-by: Robert Wolff <mahlzahn@posteo.de>
Co-committed-by: Robert Wolff <mahlzahn@posteo.de>

modules/markup/markdown/markdown_test.go

@@ -471,7 +471,7 @@ func TestColorPreview(t *testing.T) {
 		// no backticks
 		"rgb(166, 32, 64)",
 		// typo
-		"`hsI(0, 100%, 50%)`", // codespell-ignore
+		"`hsI(0, 100%, 50%)`", // codespell:ignore
 		// looks like a color but not really
 		"`hsl(40, 60, 80)`",
 	}