Fix typo in m.secret.request device event name (#1135)

* Fix typo in m.secret.request device event name

I don't think this is supposed to be plural according to the various SDKs

* Add changelog

* Update changelogs/client_server/newsfragments/1135.clarification

* Update changelogs/client_server/newsfragments/1135.clarification

Co-authored-by: Richard van der Hoff <1389908+richvdh@users.noreply.github.com>
Co-authored-by: Travis Ralston <travpc@gmail.com>

changelogs/client_server/newsfragments/1135.clarification

@@ -0,0 +1 @@
+Fix various typos throughout the specification.

content/client-server-api/modules/secrets.md

@@ -276,7 +276,7 @@ Example:
 #### Sharing
 
 To request a secret from other devices, a client sends an
-`m.secret.requests` device event with `action` set to `request` and
+`m.secret.request` device event with `action` set to `request` and
 `name` set to the identifier of the secret. A device that wishes to
 share the secret will reply with an `m.secret.send` event, encrypted
 using olm. When the original client obtains the secret, it sends an