Add the required README sections (closes #75)

Policy names five README sections that were missing or misnamed.

The Description first line now names the project, purpose, category,
WTFPL license, and author. A new Getting Started section gives a
copy-pasteable build-from-source block and gen/check/fetch usage; every
command was run against a built binary. Problem Statement and Proposed
Solution are consolidated under a new Rationale heading, keeping the
prose rather than duplicating it. A new Design section documents the
package layout: mfer/ library, internal/cli commands, internal/log and
internal/bork support, cmd/mfer entrypoint, and the committed protobuf
code. Authors is renamed Author with the canonical link.

Getting Started uses go build because the make build target invokes
protoc, which script/bootstrap does not install.

Model: opus-4-8

TODO.md

@@ -24,6 +24,11 @@ only thing left of the `chore/align-repo-policies` branch is the list below.
 
 # Completed Steps
 
+- 2026-09-21: added the required README sections — named author, license, and
+  category in the Description first line; added Getting Started (verified
+  install/usage block), Rationale (folding in Problem Statement and Proposed
+  Solution), and a Design section for the package layout; renamed Authors to
+  Author (#75)
 - 2026-08-09: added `.prettierrc`/`.prettierignore`, gave `script/fmt` and
   `script/fmt-check` one shared prettier file set via `script/prettier`, dropped
   the `|| true` that hid prettier failures, and added a node-based Dockerfile