Changelog not including commits for initial version

[patlillis]

Summary

I have auto-changelog set up in my NPM "version" script as suggested in this project's README, but when I do npm version patch the first time, commits don't get included in the generated CHANGELOG.

In addition, the section in CHANGELOG.md for the initial version does not contain the v prefix.

Steps to reproduce issue:

1. Start from empty directory
2. Run following command to initialize directory:

   git init && npm init -y && npm install --save-dev auto-changelog
   

3. Add to package.json scripts section:

   "version": "auto-changelog -p && git add CHANGELOG.md"
   

4. Create an initial commit:

   git add --all && git commit -m "initial commit"
   

5. Create an initial version:

   npm version patch
   

Expected results:

CHANGELOG.md should contain a section for v1.0.1 that contains the "initial commit" commit

Actual results:

Here is the contents of the generated CHANGELOG.md:

### Changelog

All notable changes to this project will be documented in this file. Dates are displayed in UTC.

Generated by [`auto-changelog`](https://github.com/CookPete/auto-changelog).

#### 1.0.1

> 14 July 2020

As you can see, the 1.0.1 section does NOT contain the v prefix, and does not list any commits.

[patlillis]

@cookpete any thoughts on this issue?

[cookpete]

@patlillis Sorry, I attempted to fix this as part of a refactor weeks ago, then forgot about it and didn't push.

I've just published v2.2.1 which I'm hoping will fix this problem. Let me know?

[cawa-93]

It seems that this is still relevant. I just experimented with my repository template. It has no tags.

After running auto-changelog --latest-version 20.12.11 -l false --unreleased-only -u I received:

### Changelog

All notable changes to this project will be documented in this file. Dates are displayed in UTC.

Generated by [`auto-changelog`](https://github.com/CookPete/auto-changelog).

#### 20.12.11

While experimenting, I tried to add a v0.0.0 tag to the initializing commit and run the same command again. In this scenario, a completely correct change log was generated, which contained a complete list of all commits.

[rafael-zilberman]

It seems that this is still relevant. I just experimented with my repository template. It has no tags.

After running auto-changelog --latest-version 20.12.11 -l false --unreleased-only -u I received:

### Changelog

All notable changes to this project will be documented in this file. Dates are displayed in UTC.

Generated by [`auto-changelog`](https://github.com/CookPete/auto-changelog).

#### 20.12.11

While experimenting, I tried to add a v0.0.0 tag to the initializing commit and run the same command again. In this scenario, a completely correct change log was generated, which contained a complete list of all commits.

Same happens for me, when there is not tags in the repository the generated changelog is empty.
Once I tagged the first commit with v0.0.0 the generated changelog was full with all the commits.