fix: adding missing configuration file

[nkgentile]

Adding a configuration file to the newest version (0.7.0) has broken this plugin. See #2

$ sanity start
✔ Checking configuration files...
⠴ Compiling...webpack built f49c8ff68888cf0e8c27 in 5059ms
✔ Compiling...
Failed to compile.

Error in ./node_modules/sanity-plugin-s3-dam/lib/config.js
Module not found: Error: Can't resolve 'config:s3-dam?' in './s3-dam-test/node_modules/sanity-plugin-s3-dam/lib'
 @ ./node_modules/sanity-plugin-s3-dam/lib/config.js 16:40-65
 @ ./node_modules/sanity-plugin-s3-dam/lib/schemas/s3-dam.custom-data.js
 @ ./node_modules/sanity-plugin-s3-dam/lib/schemas/s3-dam.custom-data.js (all:part:@sanity/base/schema-type)
 @ ./schemas/schema.js (part:@sanity/base/schema)
 @ ./node_modules/@sanity/base/lib/util/getNewDocumentOptions.js
 @ ./node_modules/@sanity/base/lib/_exports/_internal.js
 @ ./node_modules/@sanity/base/_internal.js
 @ ./node_modules/@sanity/default-layout/lib/defaultLayout/DefaultLayout.js
 @ ./node_modules/@sanity/default-layout/lib/defaultLayout/index.js
 @ ./node_modules/@sanity/default-layout/lib/Root.js (part:@sanity/base/root)
 @ ./node_modules/@sanity/base/lib/components/SanityRoot.js (part:@sanity/base/sanity-root)
 @ ./node_modules/@sanity/server/lib/browser/entry-dev.js
 @ multi ./node_modules/@sanity/server/lib/browser/entry-dev.js

I've added a default configuration file config.dist.json and adjusted the imports to be required (config:s3-dam)

I might need another pair of eyes on this though to make sure the types are included in the library bundle (packages/aws/src/partTypes.d.ts)?

[nkgentile]

It doesn't look like partTypes.d.ts makes it into the lib folder when building the library