message: Add: core `PuserSigner` class block comment
diff: @@ -14,9 +14,23 @@ import type {
  const { GENERIC_PROPS } = DESCRIPTORS;
  /**
  + * Create a new instance of an Abstract Signer
  + *
  + * A signer is required by design to have the following props: `provider`,
  + * `getAddress`, `signMessage` and `sendTransaction`
  + *
  + * See more: https://docs.ethers.io/ethers.js/html/api-wallet.html#signer-api
  + *
  * @class PurserSigner
  *
  * @extends Signer
  + *
  + * @param {Object} purserWalletInstance A purser instantiated wallet
  + * @param {Object} provider A provieder, most likely instantiated from Etherscan
  + *
  + * The above parameters are sent in as props of an object.
  + *
  + * @return {PurserSigner} A new instance of the class containing the expected props
  */
  export default class PurserSigner extends Signer {
  constructor({
  