use ESM module syntax & minor cleanups

The biggest change here is moving various element classes under
more scope-specific directories, which helps to avoid circular
dependencies and is just cleaner to navigate and expand in the
future.

Otherwise this is a largely uncritical port to ESM module syntax!
There are probably a number of changes and other cleanups that
remain much needed.

Whenever I make changes to tui-lib it's hard to believe it's
already been <INSERT COUNTING NUMBER HERE> years since the
previous time. First commits are from January 2017, and the
code originates a month earlier in KAaRMNoD!

1 files changed, 1 insertions, 1 deletions

diff --git a/util/telchars.js b/util/telchars.js
index 12d4095..5a5ad42 100644
--- a/util/telchars.js
+++ b/util/telchars.js
@@ -97,4 +97,4 @@ const telchars = {
   isCharacter: (buf, char) => compareBufStr(buf, char),
 }
 
-module.exports = telchars
+export default telchars