[roll third_party/pigweed] pw_console: Console user guide

- Add the Pigweed Console user guide
- Help window split into 3 separate windows
  - Upstream rst formatted user guide
  - Downstream project specific help, if provided to embed()
  - Auto-generated keybind list from all active window panes

Testing: Test Help Windows Steps 1-6
Original-Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/pigweed/+/54320

third_party/pigweed Rolled-Commits: d1a11983ec8a21f..546619f94067fdc
Roller-URL: https://ci.chromium.org/b/8840617906288985264
Cq-Cl-Tag: roller-builder:pigweed-experimental-roller
Cq-Cl-Tag: roller-bid:8840617906288985264
CQ-Do-Not-Cancel-Tryjobs: true
Change-Id: Ied8a947a56622a8d8d4e673037237d4edb59b745
Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/experimental/+/54624
Reviewed-by: Pigweed Integration Roller <pigweed-integration-roller@pigweed.google.com.iam.gserviceaccount.com>
Commit-Queue: Pigweed Integration Roller <pigweed-integration-roller@pigweed.google.com.iam.gserviceaccount.com>
diff --git a/third_party/pigweed b/third_party/pigweed
index d1a1198..546619f 160000
--- a/third_party/pigweed
+++ b/third_party/pigweed
@@ -1 +1 @@
-Subproject commit d1a11983ec8a21f7a6d8f1910a1fec6e8c33a31e
+Subproject commit 546619f94067fdcdf2b77b6a87046c31994e10fb