Added LibreSSL as an alternative to OpenSSL. Needs more testing! (0.38.16)

docs/external/tcltk.md

@@ -1,8 +1,11 @@
 # Tcl/Tk (GUI) extension (optional)
+
 - CMake option: FUN_WITH_TCLTK=ON
 - Purpose: Basic GUI functionality via Tcl/Tk.
 - Homepage: https://www.tcl.tk/
-Opcodes:
+
+## Opcodes:
+
 - OP_TK_EVAL: pops script string; pushes rc (0=OK)
 - OP_TK_RESULT: pushes last Tcl result string
 - OP_TK_LOOP: enters main event loop; pushes Nil when done
@@ -11,6 +14,8 @@ Opcodes:
 - OP_TK_BUTTON: pops text, id; creates/updates button .id; pushes rc
 - OP_TK_PACK: pops id; packs .id; pushes rc
 - OP_TK_BIND: pops command, event, id; binds; pushes rc
-Notes:
+
+## Notes:
+
 - Requires Tcl/Tk development headers/libs.
 - GUI behavior depends on your desktop environment/window manager.