Public File Sharing (#72)

* Public File Sharing

This implements public file sharing (read-only) with and without passwords (#57).

It also fixes a problem with filenames including special characters like `#` not working properly (#71).

You can share a directory or a single file, by using the new share icon on the right of the directories/files, and click on it to manage an existing file share (setting a new password, or deleting the file share).

There is some other minor cleanup and other copy updates in the README.

Closes #57
Fixes #71

* Hide UI elements when sharing isn't allowed

bewcloud.config.sample.ts

@@ -13,6 +13,7 @@ const config: PartialDeep<Config> = {
   },
   // files: {
   //   rootPath: 'data-files',
+  //   allowPublicSharing: false, // If true, public file sharing will be allowed (still requires a user to enable sharing for a given file or directory)
   // },
   // core: {
   //   enabledApps: ['news', 'notes', 'photos', 'expenses'], // dashboard and files cannot be disabled