Initial checkin of CSV table

parquet.cc is a fork of the sample CSV virtual table at
https://www.sqlite.org/src/artifact?ci=trunk&filename=ext/misc/csv.c

So far the only changes are those needed to make it compile cleanly in
C++11 mode.

README.md

@@ -1,2 +1,20 @@
 # parquet-vtable
-A SQLite vtable extension to read Parquet files
+
+A SQLite [virtual table](https://sqlite.org/vtab.html) extension to expose Parquet files as SQL tables.
+
+## Building
+
+1. Install [`parquet-cpp`](https://github.com/apache/parquet-cpp)
+2. Run `./build-sqlite` to fetch and build the SQLite dev bits
+3. Run `./parquet/make` to build the module
+  1. You will need to fixup the paths in this file to point at your local parquet-cpp folder.
+
+## Use
+
+```
+$ sqlite/sqlite3
+sqlite> .load parquet/libparquet
+sqlite> create virtual table demo USING parquet('demo.parquet');
+sqlite> select * from demo limit 1;
+...if all goes well, you'll see data here!...
+```