Add versions icons (#1141)

* Add `versions` icon

* Add `versions-files` icon

* Rename `versions-files` icon to `file-stack`

* Rename `versions` icon to `square-stack`

icons/file-stack.json

@@ -0,0 +1,16 @@
+{
+  "$schema": "../icon.schema.json",
+  "tags": [
+    "versions",
+    "multiple",
+    "copy",
+    "documents",
+    "revisions",
+    "version control",
+    "history"
+  ],
+  "categories": [
+    "files",
+    "development"
+  ]
+}

icons/file-stack.svg

@@ -0,0 +1,16 @@
+<svg
+  xmlns="http://www.w3.org/2000/svg"
+  width="24"
+  height="24"
+  viewBox="0 0 24 24"
+  fill="none"
+  stroke="currentColor"
+  stroke-width="2"
+  stroke-linecap="round"
+  stroke-linejoin="round"
+>
+  <path d="M16 2v5h5" />
+  <path d="M21 6v6.5c0 .8-.7 1.5-1.5 1.5h-7c-.8 0-1.5-.7-1.5-1.5v-9c0-.8.7-1.5 1.5-1.5H17l4 4z" />
+  <path d="M7 8v8.8c0 .3.2.6.4.8.2.2.5.4.8.4H15" />
+  <path d="M3 12v8.8c0 .3.2.6.4.8.2.2.5.4.8.4H11" />
+</svg>

icons/square-stack.json

@@ -0,0 +1,19 @@
+{
+  "$schema": "../icon.schema.json",
+  "tags": [
+    "versions",
+    "clone",
+    "copy",
+    "duplicate",
+    "multiple",
+    "revisions",
+    "version control",
+    "backup",
+    "history"
+  ],
+  "categories": [
+    "text",
+    "files",
+    "development"
+  ]
+}

icons/square-stack.svg

@@ -0,0 +1,15 @@
+<svg
+  xmlns="http://www.w3.org/2000/svg"
+  width="24"
+  height="24"
+  viewBox="0 0 24 24"
+  fill="none"
+  stroke="currentColor"
+  stroke-width="2"
+  stroke-linecap="round"
+  stroke-linejoin="round"
+>
+  <path d="M4 10c-1.1 0-2-.9-2-2V4c0-1.1.9-2 2-2h4c1.1 0 2 .9 2 2" />
+  <path d="M10 16c-1.1 0-2-.9-2-2v-4c0-1.1.9-2 2-2h4c1.1 0 2 .9 2 2" />
+  <rect width="8" height="8" x="14" y="14" rx="2" />
+</svg>