Docs/ssr readme fixes (#6932)

# Pull Request

## 📖 Description

Fixes some typos in the SSR README. Nothing major, just a little friction to getting things working :)

## ✅ Checklist

### General

- [x] I have included a change request file using `$ yarn change`
- [ ] I have added tests for my changes.
- [ ] I have tested my changes.
- [x] I have updated the project documentation to reflect my changes.
- [x] I have read the [CONTRIBUTING](https://github.com/microsoft/fast/blob/master/CONTRIBUTING.md) documentation and followed the [standards](/docs/community/code-of-conduct/#our-standards) for this project.

change/@microsoft-fast-ssr-f88fb881-5e8e-49cd-9339-b44baebaee7f.json

@@ -0,0 +1,7 @@
+{
+  "type": "prerelease",
+  "comment": "fix: typos in SSR README",
+  "packageName": "@microsoft/fast-ssr",
+  "email": "seanmonahan@microsoft.com",
+  "dependentChangeType": "patch"
+}

packages/web-components/fast-ssr/README.md

@@ -29,7 +29,7 @@ npm install --save @microsoft/fast-ssr @microsoft/fast-element
 `@microsoft/fast-ssr` requires a minimal DOM implementation to function. Install the shim by importing it. Doing so will ensure availability of certain DOM globals like `HTMLElement`, `Document`, etc.
 
 ```js
-import "@microsoft/fast-ssr/install-dom-shim";
+import "@microsoft/fast-ssr/install-dom-shim.js";
 ```
 
 Alternatively, a full DOM implementation such as [`jsdom`](https://github.com/jsdom/jsdom) or [`happy-dom`](https://github.com/capricorn86/happy-dom) can be used.
@@ -57,7 +57,7 @@ const { templateRenderer } = fastSSR();
 ### Define Custom Elements
 Ensure that the custom elements used in the template you are rendering are defined in the `customElements` registry. This example defines a component directly, but you can also import any components being used:
 ```js
-import { customElement, html, FASTElement } from "@microsoft/fast-element":
+import { attr, customElement, html, FASTElement } from "@microsoft/fast-element";
 
 @customElement({name: "my-element", template: html`<h1>${x => x.message}</h1>`})
 class MyElement extends FASTElement {