Add STAR support file with Banner Messages support task

# Common STAR Support Tasks

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## STAR Banner Messages

The STAR API has a `messages` endpoint that can be used to create, update, and delete banner messages that display globally to all users who log into STAR.

A message has the following properties:

`displayStart`: epoch timestamp in milliseconds for the local time that the banner should start being displayed. (You can use a tool like [this](https://www.epochconverter.com/) to generate the correct timestamp.)

`displayEnd`: epoch timestamp in milliseconds for the local time that the banner should stop being displayed. (You can use a tool like [this](https://www.epochconverter.com/) to generate the correct timestamp.)

`text`: string for the message that can include html elements. e.g. `<a>` tags and formatting tags like `<strong>`. Make sure quotes are escaped appropriately within the text.

`level`: corresponds to the color of the banner. Possible values: `info` = light blue, `warn` = yellow, `error` = red

`id`: the autogenerated id for the message

*Note:* Requests must be sent using basic authentication for the api user and the `On-Behalf-Of` header set to the NetID of the admin user sending the request. 

### Example Requests using TEST URL & curl

GET (use this to get the ID of messages you want to update/delete)

```

curl -u apiusername -v \

--header "Content-Type: application/json" \

--header "On-Behalf-Of: mynetid" \

-XGET “http://service:service@localhost:8080/api/v2/messages/id”

```

CREATE

```

curl -u apiusername -v \

--header "Content-Type: application/json" \

--header "On-Behalf-Of: mynetid" \

-X POST "https://test.star.doit.wisc.edu/api/v2/messages" \

--data '{ \

    "text": "<strong>Welcome to STAR!</strong>  Report your time <a href=\"https://my.wisc.edu/star\" target=\"_blank\">here</a>.", \

    "level": "info", \

    "displayStart": 1609480800000, \

    "displayEnd": 1614578400000 \

}' 

```  

UPDATE (PUT will replace the entire message object, PATCH will update a subset of the message object)

```

curl -u apiusername -v \

--header "Content-Type: application/json" \

--header "On-Behalf-Of: mynetid" \

-XPATCH “https://test.star.doit.wisc.edu/api/v2/messages/1234-abcdefg-hijklmno-pqrstuv” \

—data '{"text": "Welcome!!!", "level": "error" }'  \

```  

DELETE

``` 

curl -u apiusername -v \

--header "Content-Type: application/json" \

--header "On-Behalf-Of: mynetid" \

-XDELETE “https://test.star.doit.wisc.edu/api/v2/messages/1234-abcdefg-hijklmno-pqrstuv”

```  

### Troubleshooting

- You can make sure the the messages are being recieved by the front end by navigating to [my.wisc.edu/star](https://my.wisc.edu/star) (or whichever environment you are testing) and inspecting the network traffic for `messages.json`.

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