Make `fd` the default name of the program, but allow for the user to specify another, such as `FD=fdfind scripts/update-version.sh`.
Fix the sed command to take the filename to modify in-place and specify that the regex string is the sed-expression to execute.
This is the first alpha release of `1.0.0`: expect breaking changes.
The version suffix `alpha01.0` was chosen so that we can ship updates
that automatically update with the latter number and can prevent
auto-updates by incrementing the former number (which is not actually
a number as far as semver is concerned).
Also because crates.io sorts versions lexicographically, it will
display the wrong readme if we get to alpha10, so we pad with an extra
0 just in case we need more than 9 releases of alpha.
