New page for pub bump (#6196)

Fixes #6147 

---------

Co-authored-by: Sigurd Meldgaard <[email protected]>

src/content/tools/pub/cmd/pub-bump.md

@@ -0,0 +1,38 @@
+---
+title: dart pub bump
+description: Use dart pub bump to increase the version number of the current package.
+---
+
+_Bump_ is one of the commands of the [pub tool](/tools/pub/cmd).
+
+```plaintext
+$ dart pub bump <subcommand> [options]
+```
+
+This command increments the version number of the current package.
+Use one of the subcommands `breaking`, `major`, `minor`,
+or `patch` according to the type of increment desired. 
+
+Refer to [semver](https://semver.org/spec/v2.0.0-rc.1.html) for guidance on versioning your package.
+For example:
+
+```console
+$ dart pub bump minor
+  Updating version from 1.0.0 to 1.1.0
+  
+  Diff:
+  - version: 1.0.0
+  + version: 1.1.0
+  
+  Remember to update `CHANGELOG.md` before publishing.
+```
+
+## Options
+
+For options that apply to all pub commands, see
+[Global options](/tools/pub/cmd#global-options).
+
+### `-n, --dry-run`
+
+Reports what would change for the version number under each subcommand,
+and shows the version diff, without changing anything.