Added option for language selector

Implemented a language selector submenu that can be turned on or off by a config value.

Resolves: panr/hugo-theme-terminal#31

source/css/header.css

@@ -121,6 +121,28 @@
       }
     }
 
+    .spacer {
+      flex-grow: 1;
+    }
+
+    .language-selector {
+      position: relative;
+
+      .language-selector-actual {
+        list-style-type: none;
+        display: flex;
+        flex-direction: row;
+        color: var(--accent);
+        cursor: pointer;
+      }
+
+      .language-selector-more {
+        @mixin menu;
+        top: 35px;
+        right: 0;
+      }
+    }
+
     &-trigger {
       color: var(--accent);
       border: 2px solid;

source/js/languageSelector.js

@@ -0,0 +1,12 @@
+const mobileQuery = getComputedStyle(document.body).getPropertyValue("--phoneWidth");
+const isMobile = () => window.matchMedia(mobileQuery).matches;
+
+if(!isMobile()) {
+  languageSelector = document.getElementsByClassName("language-selector-actual")[0];
+  moreLanguagesContainer = document.getElementsByClassName("language-selector-more")[0];
+
+  languageSelector && languageSelector.addEventListener("click", e => {
+    e.stopPropagation();
+    moreLanguagesContainer.classList.toggle("hidden");
+  });
+}