test: add explanation comment

test/testExports.sh

@@ -13,9 +13,13 @@ npm init -y || exit $?
 
 rm -f index.mjs
 touch index.mjs
+# We test that all JS files we publish are importable without an extension
 tar -t -f ./supertokens-node* | grep \\.js$ | sed 's/^package\/\(.*\)\.js$/import \"supertokens-node\/\1\";/' >> index.mjs
+# We test that all JS files we publish are importable with the JS extension
 tar -t -f ./supertokens-node* | grep \\.js$ | sed 's/^package\/\(.*\)\.js$/import \"supertokens-node\/\1\.js";/' >> index.mjs
+# We test that all folders that have an index.js (outside of /lib/build) are importable as folders.
 tar -t -f --exclude package/lib/build ./supertokens-node* | grep package/.*/index\\.js$ | sed 's/^package\/\(.*\)\/index\.js$/import \"supertokens-node\/\1\";/' >> index.mjs
+# We also test that the sdk itself is importable
 echo 'import "supertokens-node";' >> index.mjs
 
 mkdir -p node_modules/supertokens-node