[core] Improve sanity dataset import documentation

packages/@sanity/core/src/commands/dataset/importDatasetCommand.js

@@ -13,15 +13,26 @@ Options
   --replace On duplicate document IDs, replace existing document with imported document
 
 Examples
+  # Import "moviedb.ndjson" from the current directory to the dataset called "moviedb"
   sanity import moviedb.ndjson moviedb
-  sanity import moviedb.ndjson moviedb --replace
+
+  # Import "moviedb.tar.gz" from the current directory to the dataset called "moviedb",
+  # replacing any documents encountered that have the same document IDs
+  sanity import moviedb.tar.gz moviedb --replace
+
+  # Import from a folder containing an ndjson file, such as an extracted tarball
+  # retrieved through "sanity dataset export".
+  sanity import ~/some/folder moviedb
+
+  # Import from a remote URL. Will download and extract the tarball to a temporary
+  # location before importing it.
   sanity import https://some.url/moviedb.tar.gz moviedb --replace
 `
 
 export default {
   name: 'import',
   group: 'dataset',
-  signature: '[FILE] [TARGET_DATASET]',
+  signature: '[FILE | FOLDER | URL] [TARGET_DATASET]',
   description: 'Import documents to given dataset from ndjson file',
   helpText,
   action: async (args, context) => {