fix pfe-card's published files

[mwcz]

---

What has changed and why

pfe-card had two files properties in its package.json, which led to no files being published. This PR corrects that.

Testing instructions

cd elements/pfe-card
npm publish --dry-run

Verify in the output that "Tarball Contents" lists files in the dist directory, like so:

npm notice === Tarball Contents ===
npm notice 1.4kB  package.json
npm notice 1.1kB  LICENSE.txt
npm notice 4.6kB  README.md
npm notice 196B   dist/pfe-card--lightdom.css
npm notice 16.8kB dist/pfe-card--lightdom.css.map
npm notice 180B   dist/pfe-card--lightdom.min.css
npm notice 202B   dist/pfe-card--lightdom.min.css.map
npm notice 19.2kB dist/pfe-card.js
npm notice 24.5kB dist/pfe-card.js.map
npm notice 16.6kB dist/pfe-card.min.js
npm notice 22.9kB dist/pfe-card.min.js.map
npm notice 23.7kB dist/pfe-card.umd.js
npm notice 24.3kB dist/pfe-card.umd.js.map
npm notice 17.3kB dist/pfe-card.umd.min.js
npm notice 22.3kB dist/pfe-card.umd.min.js.map

Before the fix, no dist files were included:

npm notice === Tarball Contents ===
npm notice 1.4kB  package.json
npm notice 1.1kB  LICENSE.txt
npm notice 4.6kB  README.md

Ready-for-merge Checklist

• Expected files: all files in this pull request are related to one feature request or issue (no stragglers)?
• Did browser testing pass?
• Did you update or add any necessary documentation (README.md, WHY.md, etc.)?
• Was this feature demo'd and the design review approved?
• Did you update the CHANGELOG.md file with a summary of this update?

[kylebuch8]

Louise Gonna Tries Metabolism

[kylebuch8]

Louise Gonna Tries Metabolism