docs: add index READMEs for docs/ and docs/notes/

Give the two linked-but-unindexed folders a browsable entry point so
directory links land on a real index instead of a bare listing.

docs/README.md

@@ -0,0 +1,34 @@
+# Docs
+
+> The design record for Typoena — the decisions, specs, and bench write-ups
+> behind the writing appliance. Start with the [ADRs](adr.md) for the
+> load-bearing choices, or the [v0.1 specs](v0.1-mvp-product.md) for what the
+> first release actually does.
+>
+> Project overview: [`../README.md`](../README.md).
+
+## Decisions & specs
+
+| Doc | What's in it |
+| --- | --- |
+| [`adr.md`](adr.md) | Architecture Decision Records — the load-bearing technical choices and why. |
+| [`v0.1-mvp-product.md`](v0.1-mvp-product.md) | v0.1 product design — boot, type one file, `Ctrl-S` to save, `Ctrl-G` to publish. |
+| [`v0.1-mvp-technical.md`](v0.1-mvp-technical.md) | v0.1 technical design — single Rust binary on `esp-idf-rs`, modules, threads, bring-up order. |
+| [`roadmap.md`](roadmap.md) | Version-by-version plan; each release is a usable artifact, not a checkpoint. |
+| [`hardware.md`](hardware.md) | Part choices for the bench build and the rationale behind them. |
+
+## Quality method
+
+| Doc | What's in it |
+| --- | --- |
+| [`qfd.md`](qfd.md) | Quality Function Deployment — turns user-facing requirements into technical HOWs. |
+| [`quality-house.md`](quality-house.md) | The 14 WHATs × 14 HOWs House of Quality, filled in. |
+| [`quality-house-empty.md`](quality-house-empty.md) | The same chassis, blank — for re-scoring from scratch. |
+
+## Bench work
+
+| Area | What's in it |
+| --- | --- |
+| [`spikes.md`](spikes.md) | Rendering & UX spikes — display/UX risks proved outside the hardware stack. |
+| [`postmortems/`](postmortems/README.md) | Bring-up debugging write-ups: what broke, the root cause, and the decisions that came out of it. |
+| [`notes/`](notes/README.md) | Longer-form essays on the thinking behind specific choices. |