Pull in prettier

We should keep ourselves honest, of course :)

package.json

@@ -0,0 +1,11 @@
+{
+  "devDependencies": {
+    "add": "^2.0.6",
+    "prettier": "^2.0.5",
+    "prettier-plugin-sh": "^0.5.0",
+    "yarn": "^1.22.4"
+  },
+  "prettier": {
+    "tabWidth": 4
+  }
+}

yarn.lock

@@ -0,0 +1,30 @@
+# THIS IS AN AUTOGENERATED FILE. DO NOT EDIT THIS FILE DIRECTLY.
+# yarn lockfile v1
+
+
+add@^2.0.6:
+  version "2.0.6"
+  resolved "https://registry.yarnpkg.com/add/-/add-2.0.6.tgz#248f0a9f6e5a528ef2295dbeec30532130ae2235"
+  integrity sha1-JI8Kn25aUo7yKV2+7DBTITCuIjU=
+
+mvdan-sh@^0.5.0:
+  version "0.5.0"
+  resolved "https://registry.yarnpkg.com/mvdan-sh/-/mvdan-sh-0.5.0.tgz#fa76f611a103595ad0f04f5d18e582892c46e87c"
+  integrity sha512-UWbdl4LHd2fUnaEcOUFVWRdWGLkNoV12cKVIPiirYd8qM5VkCoCTXErlDubevrkEG7kGohvjRxAlTQmOqG80tw==
+
+prettier-plugin-sh@^0.5.0:
+  version "0.5.0"
+  resolved "https://registry.yarnpkg.com/prettier-plugin-sh/-/prettier-plugin-sh-0.5.0.tgz#84fc56242b3fcd54c06250479c0a8f5cb35f04aa"
+  integrity sha512-i06bh7jINWXLcVjiJTnJtBmTbrA/S1waFhbtG0YFLbTIxnvI7cDWM2pAqfNf8SEsT+yB6sTkJDaPGT4ip2lFWw==
+  dependencies:
+    mvdan-sh "^0.5.0"
+
+prettier@^2.0.5:
+  version "2.0.5"
+  resolved "https://registry.yarnpkg.com/prettier/-/prettier-2.0.5.tgz#d6d56282455243f2f92cc1716692c08aa31522d4"
+  integrity sha512-7PtVymN48hGcO4fGjybyBSIWDsLU4H4XlvOHfq91pz9kkGlonzwTfYkaIEwiRg/dAJF9YlbsduBAgtYLi+8cFg==
+
+yarn@^1.22.4:
+  version "1.22.4"
+  resolved "https://registry.yarnpkg.com/yarn/-/yarn-1.22.4.tgz#01c1197ca5b27f21edc8bc472cd4c8ce0e5a470e"
+  integrity sha512-oYM7hi/lIWm9bCoDMEWgffW8aiNZXCWeZ1/tGy0DWrN6vmzjCXIKu2Y21o8DYVBUtiktwKcNoxyGl/2iKLUNGA==