Problem:
The Query Map input field on https://tools.wmflabs.org/shex-simple/wikidata/packages/shex-webapp/doc/shex-simple.html?data=Endpoint:%20https://query.wikidata.org/sparql&hideData&manifest=[]&textMapIsSparqlQuery&schemaURL=https%3A%2F%2Fwikidata-shex.wmflabs.org%2Fwiki%2FSpecial%3ASchemaText%2FO2 is not very clearly yet. We need to help people understand what to put in there and make it clearer that this is where they should continue. So we will:

• Add a placeholder query into the input field (#40)

SELECT ?id WHERE {
    # ...
}

• Put the focus into that input field on page load (#41 / #44)

Acceptance criteria:

• on page load the focus is set into the Query Map input field
• there is a placeholder text in the Query Map input field