add email address and privacy policy

[Sgtpluck]

As per digital council needs, the engineering development guide should have:

• A way for someone to contact via email and
• A link to the privacy policy,

[github-actions]

Pa11y testing results

> [email protected] pa11y-ci:sitemap
> pa11y-ci --sitemap https://engineering.18f.gov/sitemap.xml --sitemap-find https://engineering.18f.gov --sitemap-replace http://localhost:4000 --sitemap-exclude "/*.pdf"

Running Pa11y on 44 URLs:
 > http://localhost:4000/about/ - 0 errors
 > http://localhost:4000/architecture-reviews/ - 0 errors
 > http://localhost:4000/accessibility-scanning/ - 0 errors
 > http://localhost:4000/apis/ - 0 errors
 > http://localhost:4000/books-we-have-read/ - 0 errors
 > http://localhost:4000/architecture-reviews/data-act-pilot/ - 0 errors
 > http://localhost:4000/browser-testing/ - 0 errors
 > http://localhost:4000/architecture-reviews/micro-purchase/ - 0 errors
 > http://localhost:4000/continuous-deployment/ - 0 errors
 > http://localhost:4000/datastore-selection/ - 0 errors
 > http://localhost:4000/code-review/ - 0 errors
 > http://localhost:4000/development-environments/ - 0 errors
 > http://localhost:4000/frontend/ - 0 errors
 > http://localhost:4000/example-workflows/ - 0 errors
 > http://localhost:4000/css/ - 0 errors
/home/runner/work/development-guide/development-guide/node_modules/puppeteer/lib/Page.js:215
    this.emit('error', new Error('Page crashed!'));
                       ^

Error: Page crashed!
    at Page._onTargetCrashed (/home/runner/work/development-guide/development-guide/node_modules/puppeteer/lib/Page.js:215:24)
    at CDPSession.<anonymous> (/home/runner/work/development-guide/development-guide/node_modules/puppeteer/lib/Page.js:123:56)
    at CDPSession.emit (node:events:527:28)
    at CDPSession._onMessage (/home/runner/work/development-guide/development-guide/node_modules/puppeteer/lib/Connection.js:200:12)
    at Connection._onMessage (/home/runner/work/development-guide/development-guide/node_modules/puppeteer/lib/Connection.js:112:17)
    at WebSocket.<anonymous> (/home/runner/work/development-guide/development-guide/node_modules/puppeteer/lib/WebSocketTransport.js:44:24)
    at WebSocket.onMessage (/home/runner/work/development-guide/development-guide/node_modules/ws/lib/event-target.js:120:16)
    at WebSocket.emit (node:events:527:28)
    at Receiver.receiverOnMessage (/home/runner/work/development-guide/development-guide/node_modules/ws/lib/websocket.js:789:20)
    at Receiver.emit (node:events:527:28)
Emitted 'error' event on Page instance at:
    at Page._onTargetCrashed (/home/runner/work/development-guide/development-guide/node_modules/puppeteer/lib/Page.js:215:10)
    at CDPSession.<anonymous> (/home/runner/work/development-guide/development-guide/node_modules/puppeteer/lib/Page.js:123:56)
    [... lines matching original stack trace ...]
    at Receiver.emit (node:events:527:28)

[echappen]

LGTM, thanks for doing this!