support backtick as a keybinding

and bind it to gui/launcher

data/init/dfhack.keybindings.init

@@ -8,6 +8,8 @@
 # Generic dwarfmode bindings #
 ##############################
 
+keybinding add ` gui/launcher
+
 # show all current key bindings
 keybinding add Ctrl-F1 hotkeys
 keybinding add Alt-F1 hotkeys

docs/Builtin.rst

@@ -107,8 +107,8 @@ To set keybindings, use the built-in ``keybinding`` command. Like any other
 command it can be used at any time from the console, but bindings are not
 remembered between runs of the game unless re-created in `dfhack.init`.
 
-Currently, any combinations of Ctrl/Alt/Shift with A-Z, 0-9, or F1-F12 are
+Currently, any combinations of Ctrl/Alt/Shift with A-Z, 0-9, F1-F12, or ``\```
-supported.
+are supported.
 
 Possible ways to call the command:
 

library/Core.cpp

@@ -2558,6 +2558,9 @@ static bool parseKeySpec(std::string keyspec, int *psym, int *pmod, std::string
     if (keyspec.size() == 1 && keyspec[0] >= 'A' && keyspec[0] <= 'Z') {
         *psym = SDL::K_a + (keyspec[0]-'A');
         return true;
+    } else if (keyspec.size() == 1 && keyspec[0] == '`') {
+        *psym = SDL::K_BACKQUOTE;
+        return true;
     } else if (keyspec.size() == 1 && keyspec[0] >= '0' && keyspec[0] <= '9') {
         *psym = SDL::K_0 + (keyspec[0]-'0');
         return true;