Omit HEAD tag when getting last tag

[uchouT]

Describe the feature

changelogen/src/git.ts

Line 32 in 1dc8fb3

return execCommand("git describe --tags --abbrev=0", cwd)

When the HEAD is tagged, running changelogen without specifying with --from will generate changelog from head to head, which seems to be meaningless.

Maybe omit the head tag is good:
return execCommand("git describe --tags --abbrev=0 HEAD^", cwd)

Additional information

• Would you be willing to help implement this feature?