docs: add info on version control, conventional commits

docs/dev-guide/version-control.md

@@ -1,9 +1,49 @@
 # Version Control
 
-## Semantic Versioning
+## Semantic Versioning (SemVer)
+
+- A method of versioning your software packages.
+- Makes most sense for versioning software that is used by another piece
+  of software, e.g. a Python package that is installed.
+- The version number is composed of three segments: `MAJOR.MINOR.PATCH`,
+  for example `1.4.2`.
+  - MAJOR: Increments when incompatible API changes are introduced.
+    It indicates that there are significant and potentially breaking
+    changes that might require modifications in existing code.
+  - MINOR: Increments when new features are added in a backward-compatible manner.
+    It signals the addition of functionality without breaking existing code.
+    Developers can expect that their code will still work as intended.
+  - PATCH: Increments for backward-compatible bug fixes.
+    It denotes minor improvements or bug fixes that do not introduce new
+    features and do not break existing functionality.
+
+## CalVer and others
+
+- Sometimes SemVer doesn't make sense. For example, in a user-facing **software
+  service/tool**, what does a 'breaking' change denote?
+- In these cases, other conventions may be better suited.
+- At HOT, we use `YYYY.VERSION.PATCH`, in line with the developers of the ODK ecosystem.
+  - YYYY: the current year.
+  - VERSION: the release version for the current year. Resets in the next year.
+  - PATCH: a patch to the released version, typically bugfixes.
 
 ## Conventional Commits
 
+A [specification](https://www.conventionalcommits.org/en/v1.0.0/)
+for adding human and machine readable meaning to commit messages.
+
+Format: `<type>[optional scope]: <description>`
+
+Example: `feat: allow provided config object to extend other configs`
+
+A 'new' standard for commit messages.
+
+Allows for easy semantic versioning, x.x.x, as the type of increment can be
+automatically determined based on the commit types.
+
 ## Tools
 
+Some tools can make your life easier when working with conventional commits
+and SemVer.
+
 ### Commitizen