"Recoded Format" table in README.md is incorrect

[aamartin0000]

The Recoded Format table shows the mantissas as hex digits, with "f", but should be binary with only 0 or 1 (should be 23 bits, not 23 hex digits).

Also, it would be nice to show "maximum subnormal" (IEEE s 00000000 11111111111111111111111) and "minimum normal" (IEEE s 00000001 00000000000000000000000) in the table. The other interesting cases (zero, minimum subnormal, maximum normal, infinity, NaN) are shown.