add Versioning Rules section into README.md

README.md

@@ -56,9 +56,39 @@ jobs:
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 ## Description
-By using `tagpr`, the release flow can be visible and the maintainer can simply merge pull requests to complete the release.
+By using `tagpr,` the release flow can be made easier and more apparent because it can be put into a flow where the release is completed by pressing the merge button on a pull request that is automatically created.
 
-The release can be made easier and clearer because it can be put into a flow where the release is completed by pressing the merge button on a pull request that is automatically created.
+If there are differences between the last release and the main branch, tagpr generates a pull request for the next release. The tagpr considers a semver tagged commit as a release. It would be standard practice.
+
+You can leave this pull request until you want to make the next release; each time the main branch is updated, this pull request will automatically follow it.
+
+When this pull request is merged, the merge commit is automatically tagged, and GitHub Releases are created simultaneously.
+
+As mentioned at the beginning of this section, the release process becomes simply a matter of pressing the merge button.
+
+In addition, release items will be made into pull requests, allowing for visualization and review of necessary changes at the time of release. This is also important to prevent accidents.
+
+## Versioning Rules
+How tagpr proposes the next version number and how to adjust it.
+
+###  How to determine the next version number of candidate
+When creating a pull request by tagpr,  the next version number candidate is determined in the following way.
+
+- Conventional Labels: If the merged pull requests for the next release have labels named "major" or "minor," the version is determined accordingly (of course, major has priority).
+- If no conventional labels are found, the patch version is incremented.
+
+### How to adjust the next version by yourself
+You can adjust the next version number suggested by tagpr directly on the pull request created by tagpr.
+
+There are two ways to do it.
+
+####  Version file
+Edit and commit the version file specified in the .tagpr configuration file to describe the next version
+
+####  Conventional labels
+Add labels to the pull request like "tagpr:minor" or "tagpr:major." It is helpful to use a flow that does not use version files.
+
+If there is a discrepancy between the version file and the conventional labels at the time of merging, the specification in the version file takes precedence.
 
 ## Configuration
 Describe the settings in the .tagpr file directly under the repository in gitconfig format. This is automatically created the first time tagpr is run, but feel free to adjust it. The following configuration items are available