docs: rephrase the vale warnings that have a better wording

Words the alex and Microsoft styles flag where a plainer one reads as well:
disabled/special/invalid as a state, primitive, trap, hang, several, click,
first-person FAQ questions, hyphenated adverb pairs. Left as they are: Let's
Encrypt, quoted UI labels and phrases, the generated forge CLI reference, and
the middle-click gesture.

docs/swarm/notify-router.md

@@ -72,7 +72,7 @@ A flow is a graph of nodes joined by edges: one `source` node naming the forge
 event types it starts from, `match` nodes that pass when every condition
 holds, `todo` nodes that emit one todo op per recipient, and `request_reviewer`
 nodes that ask for a review. A match node can have more than one child, and
-each one runs, so one event can reach several leaves. A flow must be a tree:
+each one runs, so one event can reach more than one leaf. A flow must be a tree:
 one source, one parent for every other node, every node reachable, no children
 under a `todo` or a `request_reviewer`. The most is 64 nodes, 16
 levels deep, and 100 custom flows. A `todo` node sends to the agents an event