README is not consistent.

[drewstone]

Running yarn generate yields the following error. The fromDefs file doesn't exist it seems.

Error: Cannot find module '../src/fromDefs.ts'
Require stack:
- /Users/drewstone/code/commonwealth/edgeware-node-types/node_modules/@polkadot/typegen/scripts/polkadot-types-from-defs.cjs
    at Function.Module._resolveFilename (internal/modules/cjs/loader.js:625:15)
    at Function.Module._load (internal/modules/cjs/loader.js:527:27)
    at Module.require (internal/modules/cjs/loader.js:683:19)
    at require (internal/modules/cjs/helpers.js:16:16)
    at Object.<anonymous> (/Users/drewstone/code/commonwealth/edgeware-node-types/node_modules/@polkadot/typegen/scripts/polkadot-types-from-defs.cjs:28:10)
    at Module._compile (internal/modules/cjs/loader.js:777:30)
    at Object.Module._extensions..js (internal/modules/cjs/loader.js:788:10)
    at Module.load (internal/modules/cjs/loader.js:643:32)
    at Function.Module._load (internal/modules/cjs/loader.js:556:12)
    at Function.Module.runMain (internal/modules/cjs/loader.js:840:10)