docs: correct i2cdetect usage and ignore archived notes

The engine exposes only SMBus BYTE_DATA/WORD_DATA, so i2cdetect (which
needs SMBus QUICK or READ_BYTE) cannot scan the bus. Replace the
misleading "i2cdetect -r/-y" scan instructions with a direct i2cget
byte-data read in the README, the cover letter and the smoke test.

Also gitignore the archived internal working documents
(docs/archive-*.md).

Signed-off-by: Simone Chifari <simone.chifari@gmail.com>

.gitignore

@@ -43,11 +43,12 @@ patches/
 
 # Internal working documents (not for public repo)
 TODO.md
-submission-analysis.md
+docs/archive-submission-analysis.md
 README.local.md
 AGENTS.md
 docs/mainline-plan.md
 docs/archive-i2c-imc-driver-plan.md
+docs/archive-v3-review-fixes.md
 docs/submission/submission-instructions.md
 
 # Private Gitea CI (replaced by .github/workflows/ for public repo)