[CALCITE-5287] SQL reference page is missing from website
[CALCITE-5287] SQL reference page is missing from website

The newline at the beginning of reference.md page seems to be causing
a problem with Jekyll that ignores the .md file and fails to generate
the respective .html file.

looker-open-source/calcite,looker-open-source/calcite,looker-open-source/calcite,apache/calcite,looker-open-source/calcite,apache/calcite,looker-open-source/calcite,apache/calcite,apache/calcite,apache/calcite,apache/calcite,looker-open-source/calcite