dashboard: message dot speed is configurable

1 files changed, 8 insertions, 5 deletions

diff --git a/docs/dashboard.md b/docs/dashboard.md
index e6e3c0c..a877945 100644
--- a/docs/dashboard.md
+++ b/docs/dashboard.md
@@ -100,16 +100,19 @@ else the fresher. Then:
 * **Narrow, over a red band**: either end holds the other dormant, or the path in use
   is down (no path to the peer answers; `/peers` shows its connection as `null`).
 
-Messages this node exchanges run along its links as dots, from sender to receiver.
+Messages this node exchanges run along its links as dots, from sender to receiver, all
+at one speed: over a longer link they arrive later.
 They come from the per-peer message counts, which arrive every 2 s: what was sent and
 received since is spread over the next 2 s, at most 6 dots per link and direction,
 shared out by message kind, each kind in its colour (named in the legend; the console
 colours them alike). A dot is as large as its kind's messages were on average
-(by the size's logarithm: a ping small, a large sync message large); the slider right
-after their legend makes all dots larger or smaller, kept in the browser. A picture
+(by the size's logarithm: a ping small, a large sync message large); the `size` slider
+right after their legend makes all dots larger or smaller, and the `speed` slider after
+it makes them run faster or slower (0.1 to 0.9 map units per millisecond, 0.3 at
+first: a link of 200 in about 0.7 s); both are kept in the browser. A picture
 of the traffic, not a record of it; links between other members show none.
-`messages: on` after the slider hides them (`messages: off` shows them again; the
-legend and the slider greyed meanwhile); the choice is kept in the browser.
+`messages: on` after the sliders hides them (`messages: off` shows them again; the
+legend and the sliders greyed meanwhile); the choice is kept in the browser.
 
 A label on the map that changes, a round trip or a node's name, breathes once: it
 glows around its new text and fades (not where the system asks for reduced motion).