Feat: initial project plan draft

Add a first draft of the high-level project plan to the repository's README.

README.md

@@ -1,2 +1,31 @@
-# xkpasswd-js
-The official JavaScript port of the Crypt::HSXKPasswd Perl module.
+# XKPasswdJS — The Official JavaScript Port of Crypt::HSXKPasswd
+
+[Bart Busschots](https://www.bartb.ie/) created the [Crypt::HSXKPasswd](https://metacpan.org/pod/Crypt::HSXKPasswd) Perl module to be a liberally licensed ([2-clause BSD](https://opensource.org/licenses/BSD-2-Clause)) password generator for producing secure but memorable passwords using the word-based approach made famous by the [*Correct Horse Battery Staple* XKCD comic](https://xkcd.com/936/).
+
+![To anyone who understands information theory and security and is in an infuriating argument with someone who does not (possibly involving mixed case), I sincerely apologize.](https://imgs.xkcd.com/comics/password_strength.png)
+
+Bart is leading this port of the Perl module to JavaScript with the [NosillaCast community](https://podfeet.com/slack) as part of the on-going Programming By Stealth blog/podcast series](https://pbs.bartificer.net) he produces with [Allison Sheridan](https://www.podfeet.com/blog/about/).
+
+## Project Plan
+
+The plan is to develop this port in the following broad stages:
+
+1. **Project Skeleton** — project infrastructure and specification for direct port
+   * Bart will work mostly solo with only typo-like pull requests accepted
+   * Outcomes:
+     * ULM Class Diagram defining the API for the direct port
+     * Contribution guides for developers including a project code style, a Git branching policy, and a style guide for Git commits
+     * Configuration files for the project tooling, specically WebPack (bundler), JSLint (code linter), JSDoc (documentation generator), and Jest (test suite)
+     * Automations/Scripts to build the project, run the test suite, and build the documentation
+2. **Direct Port** — implementation of a feature-for-feature port of the Perl module to JavaScript
+   * Pull requests implementing the documented design and following the contribution guidelines will be gratefully accepted
+   * The issue tracker will be opened and used to track bugs and enhancement requests
+   * Outcomes:
+     * An ES6 JavaScript module implementing the documented API
+     * Detailed documentation
+     * A Jest test suite with full code coverage
+     * An officual NPM package for the module
+3. **Maintenance & Enhancement** — bug fixes, security patches, and feature enhancements
+   * Details to be agreed later based on the experiences from phase 2.
+
+**The project is currently in phase 1 — project skeleton**.