Update CI instructions in Readme

README.md

@@ -78,10 +78,29 @@ details.
   Otherwise if you update a patch then the change may not be reflected on
   subsequent CI runs.
 
-  E.g., for CircleCI: before loading/saving your cache run
-  `cat patches/* | md5 > patches.hash` and then update your hash key to include
-  a checksum of that file,
-  `{{ checksum "yarn.lock" }}-{{ checksum "patches.hash" }}`.
+
+### CircleCI
+Create a hash of your patches before loading/saving your cache. If using a Linux machine, run `md5sum patches/* > patches.hash`. If running on a macOS machine,  use `md5 patches/* > patches.hash`
+```yaml
+- run:
+    name: patch-package hash
+    command: md5sum patches/* > patches.hash
+```
+
+Then, update your hash key to include a checksum of that file:
+```yaml
+- restore_cache:
+    key: app-node_modules-v1-{{ checksum "yarn.lock" }}-{{ checksum "patches.hash" }}
+```  
+
+As well as the save_cache
+```yaml
+- save_cache:
+    key: app-node_modules-v1-{{ checksum "yarn.lock" }}-{{ checksum "patches.hash" }}
+    paths:
+      - ./node_modules
+```
+
 
 ## Usage