Changing the default quality level

At the moment the default quality level when encoding is 11, when using `BrotliEncoderParams::default()`, [see source](https://docs.rs/brotli/3.3.4/src/brotli/enc/encode.rs.html#389).

I was wondering if there is any interest in changing the default to something more reasonable, as 11 is the highest and takes an extremely long time.