Re-introduce wp_title implementation

** Why are these changes being introduced:

* The legacy parent theme had this function in place, which didn't seem
  necessary as wp_title is provided by WordPress already. However, it
  doesn't seem that the documentation for wp_title is accurate - and
  this function is actually needed.

** Relevant ticket(s):

* https://mitlibraries.atlassian.net/browse/lm-444

** How does this address that need:

* This re-introduces the customization function from the legacy theme.

** Document any side effects to this change:

* None - although this function shouldn't be necessary - yet it is.

Author: matt-bernhardt

web/app/themes/mitlib-parent/functions.php

@@ -258,6 +258,38 @@ function setup_scripts_styles() {
 }
 add_action( 'wp_enqueue_scripts', 'Mitlib\Parent\setup_scripts_styles' );
 
+/**
+ * Creates a nicely formatted and more specific title element text
+ * for output in head of document, based on current view.
+ *
+ * @param string $title Default title text for current view.
+ * @param string $sep Optional separator.
+ * @return string Filtered title.
+ */
+function customize_title( $title, $sep ) {
+	global $paged, $page;
+
+	if ( is_feed() ) {
+		return $title; }
+
+	// Add the site name.
+	$title .= get_bloginfo( 'name' );
+
+	// Add the site description for the home/front page.
+	$site_description = get_bloginfo( 'description', 'display' );
+	if ( $site_description && ( is_home() || is_front_page() ) ) {
+		$title = "$title $sep $site_description";
+	}
+
+	// Add a page number if necessary.
+	if ( $paged >= 2 || $page >= 2 ) {
+		$title = "$title $sep " . sprintf( 'Page %s', max( $paged, $page ) );
+	}
+
+	return $title;
+}
+add_filter( 'wp_title', 'Mitlib\Parent\customize_title', 10, 2 );
+
 /**
  * Binds JS handlers to make Theme Customizer preview reload changes asynchronously.
  */