CCM-8585: use post in curl commands

Author: alexnuttall

lambdas/backend-api/README.md

@@ -33,7 +33,7 @@ curl --location 'https://<apig_id>.execute-api.eu-west-2.amazonaws.com/main/v1/t
 Will update a template
 
 ```bash
-curl --location 'https://<apig_id>.execute-api.eu-west-2.amazonaws.com/main/v1/template/<string>' \
+curl -X POST --location 'https://<apig_id>.execute-api.eu-west-2.amazonaws.com/main/v1/template/<string>' \
 --header 'Content-Type: application/json' \
 --header 'Accept: application/json' \
 --header 'Authorization: ••••••' \
@@ -61,7 +61,7 @@ curl --location 'https://<apig_id>.execute-api.eu-west-2.amazonaws.com/main/v1/t
 Will create a single template.
 
 ```bash
-curl --location 'https://<apig_id>.execute-api.eu-west-2.amazonaws.com/main/v1/template' \
+curl -X POST --location 'https://<apig_id>.execute-api.eu-west-2.amazonaws.com/main/v1/template' \
 --header 'Content-Type: application/json' \
 --header 'Accept: application/json' \
 --header 'Authorization: ••••••' \
@@ -78,7 +78,7 @@ curl --location 'https://<apig_id>.execute-api.eu-west-2.amazonaws.com/main/v1/t
 Will create a single letter template. The CSV form part is optional. Do not set a content type header as this must be auto-generated by curl, so that it includes a form-data boundary.
 
 ```bash
-curl --location 'https://<apig_id>.execute-api.eu-west-2.amazonaws.com/<env>/v1/letter-template' \
+curl -X POST --location 'https://<apig_id>.execute-api.eu-west-2.amazonaws.com/<env>/v1/letter-template' \
 --header 'Accept: application/json' \
 --header 'Authorization: ••••••' \
 --form 'letterPdf=@<path_to_pdf>;type=application/pdf;filename=<string>' \