symbol-def (#1)

Started branch to add `pform`, ended up pulling in `symbol-def` from the forums. Also adds the editor code from the T-Deck.

Reviewed-on: kyle/ulisp-picocalc#1
Co-authored-by: Kyle Isom <kyle@imap.cc>
Co-committed-by: Kyle Isom <kyle@imap.cc>

picocalc/ulisp-arm.ino

@@ -10498,6 +10498,7 @@ void setup () {
   initkybd();
 #endif
   pfstring(PSTR("uLisp 4.7b "), pserial); pln(pserial);
+  loadimage(NULL);
 }
 
 // Read/Evaluate/Print loop