docs(readDICOMTags): Add API usage

Author: floryst

doc/content/api/browser_io.md

@@ -69,6 +69,17 @@ If the files are known to be from a single, sorted series, the last argument can
 
 The used `webWorkerPool` is returned to enable resource cleanup by calling `.terminateWorkers()`.
 
+## readDICOMTags(fileList, tags=[]) -> { tags, webWorkerPool }
+
+Read tags from several DICOM [Files](https://developer.mozilla.org/en-US/docs/Web/API/File)'s or [Blobs](https://developer.mozilla.org/en-US/docs/Web/API/Blob)'s stored in an [Array](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array) or [FileList](https://developer.mozilla.org/en-US/docs/Web/API/FileList).
+
+Tags should be of the form `"GGGG|EEEE"`, where `GGGG` is the group ID in hex and `EEEE` is the element ID in hex. As an example, "0010|0010" is the PatientID.
+Hexadecimal strings are treated case-insensitively.
+
+Returns a tags property that contains an object with keys being the tags and the values being the tags' values.
+
+The used `webWorkerPool` is returned to enable resource cleanup by calling `.terminateWorkers()`.
+
 ## writeImageArrayBuffer(webWorker, useCompression, image, fileName, mimeType) ->  { webWorker, [arrayBuffer](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/ArrayBuffer) }
 
 Write an image to a an [ArrayBuffer](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/ArrayBuffer).