Restructured the footer, added useful links and removed unused content

changes/changelog.d/footer.enhancement

+Restructured the footer, added useful links and removed unused content

front/src/components/Footer.vue

+<template>
+  <footer id="footer" class="ui vertical footer segment">
+    <div class="ui container">
+      <div class="ui stackable equal height stackable grid">
+        <div class="four wide column">
+          <h4 v-translate class="ui header">
+            <translate :translate-params="{instanceName: instanceHostname}" >About %{instanceName}</translate>
+          </h4>
+          <div class="ui link list">
+            <router-link class="item" to="/about">
+              <translate>About page</translate>
+            </router-link>
+            <div class="item" v-if="version">
+              <translate :translate-params="{version: version}" >Version %{version}</translate>
+            </div>
+            <a @click="switchInstance" class="item" >
+              <translate>Use another instance</translate>
+            </a>
+          </div>
+          <div class="ui form">
+            <div class="ui field">
+              <label><translate>Change language</translate></label>
+              <select class="ui dropdown" v-model="$language.current">
+                <option v-for="(language, key) in $language.available" :key="key" :value="key">{{ language }}</option>
+              </select>
+            </div>
+          </div>
+        </div>
+        <div class="four wide column">
+          <h4 v-translate class="ui header">Using Funkwhale</h4>
+          <div class="ui link list">
+            <a href="https://docs.funkwhale.audio" class="item" target="_blank"><translate>Documentation</translate></a>
+            <a href="https://docs.funkwhale.audio/users/apps.html" class="item" target="_blank"><translate>Mobile and desktop apps</translate></a>
+            <div role="button" class="item" @click="$emit('show:shortcuts-modal')"><translate>Keyboard shortcuts</translate></div>
+          </div>
+        </div>
+        <div class="four wide column">
+          <h4 v-translate class="ui header">Getting help</h4>
+          <div class="ui link list">
+            <a href="https://socialhub.network/c/projects/funkwhale" class="item" target="_blank"><translate>Support forum</translate></a>
+            <a href="https://riot.im/app/#/room/#funkwhale-troubleshooting:matrix.org" class="item" target="_blank"><translate>Chat room</translate></a>
+            <a href="https://code.eliotberriot.com/funkwhale/funkwhale/issues" class="item" target="_blank"><translate>Issue tracker</translate></a>
+          </div>
+        </div>
+        <div class="four wide column">
+          <h4 v-translate class="ui header">About Funkwhale</h4>
+          <div class="ui link list">
+            <a href="https://funkwhale.audio" class="item" target="_blank"><translate>Official website</translate></a>
+            <a href="https://contribute.funkwhale.audio" class="item" target="_blank"><translate>Contribute</translate></a>
+            <a href="https://code.eliotberriot.com/funkwhale/funkwhale" class="item" target="_blank"><translate>Source code</translate></a>
+          </div>
+          <div class="ui hidden divider"></div>
+          <p>
+            <translate>The funkwhale logo was kindly designed and provided by Francis Gading.</translate>
+          </p>
+        </div>
+      </div>
+    </div>
+  </footer>
+</template>
+
+<script>
+import {mapState} from 'vuex'
+
+
+export default {
+  props: ['version'],
+  methods: {
+    switchInstance () {
+      let confirm = window.confirm(this.$gettext('This will erase your local data and disconnect you, do you want to continue?'))
+      if (confirm) {
+        this.$store.commit('instance/instanceUrl', null)
+      }
+    },
+  },
+  computed: {
+    ...mapState({
+      messages: state => state.ui.messages
+    }),
+    instanceHostname () {
+      let url = this.$store.state.instance.instanceUrl
+      let parser = document.createElement('a');
+      parser.href = url
+      return parser.hostname
+    },
+    suggestedInstances () {
+      let instances = [this.$store.getters['instance/defaultUrl'](), 'https://demo.funkwhale.audio']
+      return instances
+    },
+  }
+}
+</script>
+<style scoped>
+  footer p {
+    color: grey;
+  }
+</style>