Add bufferPath to config, support bufferPath symlink (#27)

* Add bufferPath to config, support bufferPath symlink

* defaultPath before checking realpath

* Move code for retrieving buffer path into its own file

* Do the realpathSync() call for the whole final file path, to allow the buffer file to be a symlink

---------

Co-authored-by: Jonatan Heyman <jonatan@heyman.info>

electron/config.js

@@ -28,6 +28,7 @@ const schema = {
             "allowBetaVersions": {type: "boolean", default: false},
             "enableGlobalHotkey": {type: "boolean", default: false},
             "globalHotkey": {type: "string", default: "CmdOrCtrl+Shift+H"},
+            "bufferPath" : {type: "string", default: ""},
         },
     },
 
@@ -51,6 +52,7 @@ const defaults = {
         allowBetaVersions: false,
         enableGlobalHotkey: false,
         globalHotkey: "CmdOrCtrl+Shift+H",
+        bufferPath: "",
     },
     theme: "system",
 }