Adds link to Media Capture docs in main TOC

Change-Id: I398236d9ff8b66d37b7d9603b8d569e4059a7c96
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/4793728
Commit-Queue: Mark Foltz <mfoltz@chromium.org>
Reviewed-by: Mark Foltz <mfoltz@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1185904}
diff --git a/docs/README.md b/docs/README.md
index 1114654b..08f0375d 100644
--- a/docs/README.md
+++ b/docs/README.md
@@ -349,6 +349,8 @@
 *   [Latency tracing](media/latency_tracing.md) - How to use the
     `"audio.latency"` tracing category to measure audio latency.
 *   [Piranha Plant](piranha_plant.md) - Future architecture of MediaStreams
+*   [Media Capture](media/capture/README.md) - Features and APIs that enable the
+    browser to capture pixels and audio from itself or the underlying OS.
 *   [Video Encode Accelerator Tests](media/gpu/veatest_usage.md) - How to
     use the accelerated video encoder test program.
 *   [Video Decoder Tests](media/gpu/video_decoder_test_usage.md) - Running the