Add CHANGELOG.md, update CONTRIBUTING.md and fix typo in README.md

Author: hipitihop

CHANGELOG.md

@@ -0,0 +1,10 @@
+# Changelog
+
+All notable changes to this project will be documented in this file.
+
+The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
+and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
+
+##  [Unreleased]
+### Added
+- Merged PR #34 `::async-flow-fx/notify` NOP event handler for minimal flow signals. See ["Event Messaging" in README.md](https://github.com/day8/re-frame-async-flow-fx#event-messaging)

CONTRIBUTING.md

@@ -45,15 +45,17 @@ karma start     # to run the tests with an auto watcher
 
 If possible provide:
 
-* Code that fixes the bug
-* Failing tests which pass with the new changes
-* Improvements to documentation to make it less likely that others will run into issues (if relevant).
+- Code that fixes the bug.
+- Failing tests which pass with the new changes.
+- Improvements to documentation to make it less likely that others will run into issues (if relevant).
+- Add the change to the Unreleased section of [CHANGELOG.md](CHANGELOG.md)
 
 ## Pull requests for features
 
 If possible provide:
 
-* Code that implements the new feature
-* Tests to cover the new feature including all of the code paths
-* Docstrings for functions
-* Documentation examples
+- Code that implements the new feature
+- Tests to cover the new feature including all of the code paths
+- Docstrings for functions
+- Documentation examples
+- Add the change to the Unreleased section of [CHANGELOG.md](CHANGELOG.md)

README.md

@@ -433,17 +433,17 @@ Or, to dispatch a server error event if a status of 500 or above has been seen
 In an async flow it is often useful to dispatch an event to indicate success or failure of
 some process. However, this event may not actually have to do anything. `re-frame` will issue a 
 warning if an event is dispatched that has not been registered by `reg-event-db` or `reg-event-fx`.
-If you use this pattern alot it quickly becomes inconvienent to register multiple no-op handlers to 
+If you use this pattern a lot it quickly becomes inconvenient to register multiple no-op handlers to 
 avoid this warning.
 
 To address this issue we provide a no-op handler `::async-flow-fx/notify` which you can use in the 
 following way.
 
 ```clj
-[{:when :seen?        :events [[::async-flow-fx/notify :success-db-connect]]   
+[{:when :seen? :events [[::async-flow-fx/notify :success-db-connect]]   
   :dispatch-n '([:do-query-user] [:do-query-site-prefs])}
  ...]}]
- ```
+```
 
 Note  `::async-flow-fx/notify` doesn't do anything special and if you like you can add your own 
 no-op event.