Add check keyword to docstring

src/bibtex.jl

@@ -1,5 +1,5 @@
 """
-    import_bibtex(input)
+    import_bibtex(input; check = :error)
 Import a BibTeX file or parse a BibTeX string and convert it to the internal bibliography format.
 The `check` keyword argument can be set to `:none` (or `nothing`), `:warn`, or `:error` to raise appropriate logs.
 """