chore(docs): add Fastly to table in README and add badges to Fastly README (#800)

This PR adds badges for Fastly to the table in the main README.md and in
the Fastly README.

You can see what these pages look like on this branch:
-
[README.md](https://github.com/launchdarkly/js-core/blob/5981d32eec5c02405d042e800eba5c7ef2e2dcf2/README.md)
-
[packages/sdk/fastly/README.md](https://github.com/launchdarkly/js-core/blob/5981d32eec5c02405d042e800eba5c7ef2e2dcf2/packages/sdk/fastly/README.md)

Author: ldhenry

README.md

@@ -10,6 +10,7 @@ This includes shared libraries, used by SDKs and other tools, as well as SDKs.
 | [@launchdarkly/akamai-server-base-sdk](packages/sdk/akamai-base/README.md)     | [![NPM][sdk-akamai-base-npm-badge]][sdk-akamai-base-npm-link]     | [Akamai Base][package-sdk-akamai-base-issues]     | [![Actions Status][sdk-akamai-base-ci-badge]][sdk-akamai-base-ci]     |
 | [@launchdarkly/akamai-server-edgekv-sdk](packages/sdk/akamai-edgekv/README.md) | [![NPM][sdk-akamai-edgekv-npm-badge]][sdk-akamai-edgekv-npm-link] | [Akamai EdgeKV][package-sdk-akamai-edgekv-issues] | [![Actions Status][sdk-akamai-edgekv-ci-badge]][sdk-akamai-edgekv-ci] |
 | [@launchdarkly/cloudflare-server-sdk](packages/sdk/cloudflare/README.md)       | [![NPM][sdk-cloudflare-npm-badge]][sdk-cloudflare-npm-link]       | [Cloudflare][package-sdk-cloudflare-issues]       | [![Actions Status][sdk-cloudflare-ci-badge]][sdk-cloudflare-ci]       |
+| [@launchdarkly/fastly-server-sdk](packages/sdk/fastly/README.md)               | [![NPM][sdk-fastly-npm-badge]][sdk-fastly-npm-link]               | [Fastly][package-sdk-fastly-issues]               | [![Actions Status][sdk-fastly-ci-badge]][sdk-fastly-ci]               |
 | [@launchdarkly/node-server-sdk](packages/sdk/server-node/README.md)            | [![NPM][sdk-server-node-npm-badge]][sdk-server-node-npm-link]     | [Node.js Server][package-sdk-server-node-issues]  | [![Actions Status][sdk-server-node-ci-badge]][sdk-server-node-ci]     |
 | [@launchdarkly/vercel-server-sdk](packages/sdk/vercel/README.md)               | [![NPM][sdk-vercel-npm-badge]][sdk-vercel-npm-link]               | [Vercel][package-sdk-vercel-issues]               | [![Actions Status][sdk-vercel-ci-badge]][sdk-vercel-ci]               |
 | [@launchdarkly/react-native-client-sdk](packages/sdk/react-native/README.md)   | [![NPM][sdk-react-native-npm-badge]][sdk-react-native-npm-link]   | [React-Native][package-sdk-react-native-issues]   | [![Actions Status][sdk-react-native-ci-badge]][sdk-react-native-ci]   |
@@ -108,6 +109,16 @@ We encourage pull requests and other contributions from the community. Check out
 [sdk-cloudflare-dm-badge]: https://img.shields.io/npm/dm/@launchdarkly/cloudflare-server-sdk.svg?style=flat-square
 [sdk-cloudflare-dt-badge]: https://img.shields.io/npm/dt/@launchdarkly/cloudflare-server-sdk.svg?style=flat-square
 [package-sdk-cloudflare-issues]: https://github.com/launchdarkly/js-core/issues?q=is%3Aissue+is%3Aopen+label%3A%22package%3A+sdk%2Fcloudflare%22+
+[//]: # 'sdk/fastly'
+[sdk-fastly-ci-badge]: https://github.com/launchdarkly/js-core/actions/workflows/fastly.yml/badge.svg
+[sdk-fastly-ci]: https://github.com/launchdarkly/js-core/actions/workflows/fastly.yml
+[sdk-fastly-npm-badge]: https://img.shields.io/npm/v/@launchdarkly/fastly-server-sdk.svg?style=flat-square
+[sdk-fastly-npm-link]: https://www.npmjs.com/package/@launchdarkly/fastly-server-sdk
+[package-sdk-fastly-issues]: https://github.com/launchdarkly/js-core/issues?q=is%3Aissue+is%3Aopen+label%3A%22package%3A+sdk%2Ffastly%22+
+[sdk-fastly-ghp-badge]: https://img.shields.io/static/v1?label=GitHub+Pages&message=API+reference&color=00add8
+[sdk-fastly-ghp-link]: https://launchdarkly.github.io/js-core/packages/sdk/fastly/docs/
+[sdk-fastly-dm-badge]: https://img.shields.io/npm/dm/@launchdarkly/fastly-server-sdk.svg?style=flat-square
+[sdk-fastly-dt-badge]: https://img.shields.io/npm/dt/@launchdarkly/fastly-server-sdk.svg?style=flat-square
 [//]: # 'sdk/server-node'
 [sdk-server-node-npm-badge]: https://img.shields.io/npm/v/@launchdarkly/node-server-sdk.svg?style=flat-square
 [sdk-server-node-npm-link]: https://www.npmjs.com/package/@launchdarkly/node-server-sdk

packages/sdk/fastly/README.md

@@ -1,5 +1,11 @@
 # LaunchDarkly SDK for Fastly
 
+[![NPM][sdk-fastly-npm-badge]][sdk-fastly-npm-link]
+[![Actions Status][sdk-fastly-ci-badge]][sdk-fastly-ci]
+[![Documentation][sdk-fastly-ghp-badge]][sdk-fastly-ghp-link]
+[![NPM][sdk-fastly-dm-badge]][sdk-fastly-npm-link]
+[![NPM][sdk-fastly-dt-badge]][sdk-fastly-npm-link]
+
 The LaunchDarkly SDK for Fastly is designed for use in [Fastly Compute Platform](https://www.fastly.com/documentation/guides/compute/). It follows the server-side LaunchDarkly model for multi-user contexts. It is not intended for use in desktop and embedded systems applications.
 
 ## Install