console.lua: replace font script-opt with monospace_font

Allow configuring the monospace font without also changing the
proportional font. The proportional font is configured with the standard
--osd-font.

DOCS/interface-changes/console-font.txt

@@ -0,0 +1,2 @@
+add `console-monospace_font` script-opt
+remove `console-font` script-opt

DOCS/man/console.rst

@@ -124,12 +124,12 @@ option. The configuration syntax is described in `mp.options functions`_.
 Configurable Options
 ~~~~~~~~~~~~~~~~~~~~
 
-``font``
-    The font name.
+``monospace_font``
+    Default: platform dependent
 
-    When necessary to align completions in a grid, a monospace font depending on
-    the platform is the default. When there are no completions, ``--osd-font``
-    is the default.
+    The monospace font used when there are completions to align in a grid.
+
+    When there are no completions, ``--osd-font`` is used.
 
 ``font_size``
     Default: 24

player/lua/console.lua

@@ -29,7 +29,7 @@ local platform = detect_platform()
 
 -- Default options
 local opts = {
-    font = "",
+    monospace_font = "",
     font_size = 24,
     border_size = 1.65,
     background_alpha = 80,
@@ -126,14 +126,14 @@ local function get_property_cached(name, def)
 end
 
 local function get_font()
-    if opts.font ~= "" then
-        return opts.font
-    end
-
     if not has_completions then
         return
     end
 
+    if opts.monospace_font ~= "" then
+        return opts.monospace_font
+    end
+
     -- Pick a better default font for Windows and macOS
     if platform == "windows" then
         return "Consolas"