Add explain crontab tool

src/views/ExplainCrontab.vue

@@ -0,0 +1,47 @@
+<template>
+  <h2 class="tool-title">Explain crontab</h2>
+  <hr class="mt-5 mb-5">
+
+  <div class="input-group">
+    <label for="data">Data</label>
+    <input id="data" class="input" v-model="toolData.data" placeholder="* * * * *" type="text">
+  </div>
+
+  <hr class="mt-5 mb-5">
+
+  <div class="input-group">
+    <label for="result">Result</label>
+    <textarea id="result" v-model="toolResult" style="height: 150px"></textarea>
+  </div>
+</template>
+
+<script>
+import cronstrue from 'cronstrue';
+import { unproxy } from "@/utils/unproxy";
+
+export default {
+  data() {
+    return {
+      toolData: {
+        data: '* * * * *',
+      },
+    };
+  },
+  computed: {
+    toolResult() {
+      try {
+        return cronstrue.toString(this.toolData.data, {
+          use24HourTimeFormat: true,
+          verbose: true,
+        });
+      } catch (e) {
+        return 'invalid syntax';
+      }
+    },
+  },
+}
+</script>
+
+<style lang="scss">
+
+</style>