0.3.0 release

• fix sign() for -0 (0x8000)
• update unit test
• update GitHub actions
• minor edits

0.2.1 release

• update GitHub actions
• update examples
• minor edits

0.2.0 release

• sync with float16 version 0.3.0
• remove printable interface to fix issue #12 float 16 (footprint).

0.1.0 release

• initial version based upon float16