Versioning section small refactor

Author: codebien

docs/sources/k6/next/reference/versioning-and-stability-guarantees.md

@@ -22,15 +22,23 @@ If you believe an API should be added to this allow list but is currently missin
 
 k6 strictly follows [Semantic Versioning 2.0.0](https://semver.org/) versioning scheme. This versioning scheme defines three kinds of software versions.
 
-#### Major version
+### Breaking change
+
+As per the [Semantic Versioning 2.0.0](https://semver.org/spec/v2.0.0.html) specification, we define a breaking change as a change to k6 that's not backward compatible.
+
+Breaking changes imply that the consumer of k6 is expected to make some effort to adapt to the changes being made.
+
+Although it's possible that, in certain cases, the new major version containing breaking changes might be compatible with the previous version, this isn't expected.
+
+### Major version
 
 A major version contains backward incompatible API changes.
 
 Quoting the [SemVer 2.0.0 specification on major versions](https://semver.org/#spec-item-8) directly:
 
 > *Major version X (X.y.z | X \> 0\) **MUST** be incremented if any backward-incompatible changes are introduced to the public API. This may also include minor and patch-level changes. Patch and minor versions **MUST** be reset to 0 when the major version is incremented.*
 
-#### Minor version
+### Minor version
 
 A minor version contains backward-compatible API additions/changes.
 
@@ -41,22 +49,14 @@ Quoting the [SemVer 2.0.0 specification on minor versions](https://semver.org/#s
 > *It MAY be incremented if substantial new functionality or improvements are introduced within the private code.*
 > *It MAY include patch-level changes. The patch version MUST be reset to 0 when the minor version is incremented.*
 
-#### Patch version
+### Patch version
 
 A patch version contains bug fixes **that do not affect** the API.
 
 Quoting the [SemVer 2.0.0 specification on patch versions](https://semver.org/#spec-item-6) directly:
 
 > *Patch version Z (x.y.Z | x \> 0\) **MUST** be incremented if only backward compatible bug fixes are introduced. A bug fix is defined as an internal change that fixes incorrect behavior.*
 
-### Breaking change
-
-As per the [Semantic Versioning 2.0.0](https://semver.org/spec/v2.0.0.html) specification, we define a breaking change as a change to k6 that's not backward compatible.
-
-Breaking changes imply that the consumer of k6 is expected to make some effort to adapt to the changes being made.
-
-Although it's possible that, in certain cases, the new major version containing breaking changes might be compatible with the previous version, this isn't expected.
-
 ## Release strategy
 
 A k6 release is a set of changes that updates or adds new functionalities to the product, made globally available under a unique and new identifiable version.