metrics: memd: add links to metrics/memd/README.md

BUG=none
TEST=none

Change-Id: I302654ae68ac334a2fd3e698f57e063dc2c37afd
Reviewed-on: https://chromium-review.googlesource.com/1118907
Commit-Ready: Luigi Semenzato <semenzato@chromium.org>
Tested-by: Luigi Semenzato <semenzato@chromium.org>
Reviewed-by: Mike Frysinger <vapier@chromium.org>
diff --git a/README.md b/README.md
index e4e0429..4c38112 100644
--- a/README.md
+++ b/README.md
@@ -67,6 +67,7 @@
 | [libweave](./libweave/) | Library for cloud messaging |
 | [login_manager](./login_manager/) | Session manager for handling the life cycle of the main session (e.g. Chrome) |
 | [lorgnette](./lorgnette/) | Daemon for managing attached USB scanners via [SANE](https://en.wikipedia.org/wiki/Scanner_Access_Now_Easy) |
+| [memd](./metrics/memd/) | Daemon that logs memory-related data and events |
 | [metrics](./metrics/) | Client side user metrics collection |
 | [midis](./midis/) | [MIDI](https://en.wikipedia.org/wiki/MIDI) service |
 | [mist](./mist/) | Modem USB Interface Switching Tool |
diff --git a/metrics/README.md b/metrics/README.md
index 422a6b8..84c967d 100644
--- a/metrics/README.md
+++ b/metrics/README.md
@@ -102,6 +102,11 @@
 
 - `shill.`
 
+# Memory Daemon
+
+The [memd](./memd/) subdirectory contains a daemon that collects data at high
+frequency during episodes of heavy memory pressure.
+
 # Further Information
 
 See