adding in meson building for easier dependency management

meson.build

@@ -0,0 +1,9 @@
+project('flowy', 'cpp')
+
+gtkmm_dep = dependency('gtkmm-4.0', version: '>= 4.6.0')
+
+exe_file = executable('flowy',
+  'src/main.cpp',
+  dependencies: gtkmm_dep,
+  win_subsystem: 'windows',
+)

meson.sh

@@ -0,0 +1,12 @@
+#!/bin/sh
+
+# incase it's not set up already
+meson setup build
+
+echo "Compiling..."
+cd build
+meson compile
+
+echo "Running..."
+./flowy
+