float8: Add float8 package which implements values in 8-bit floating-point notation.
cs: Update readme.
float8: Handle the floating-point value 0 in New and add test cases.
float8: Remove Normalize function since all values from New are normalized.
float8: Implement Float32 method for Float8.
float8: Implement String method for Float8.
float8: Update comment of the Float32 method.
float8: Add test case for Add.
float8: Add the function Add which computes the sum of two Float8 values.
float8: More informative error from Add on exponent overflows and underflows.