Bump dokka-maven-plugin from 1.8.10 to 1.8.20 (#415)

Bumps [dokka-maven-plugin](https://github.com/Kotlin/dokka) from 1.8.10 to 1.8.20.
- [Release notes](https://github.com/Kotlin/dokka/releases)
- [Commits](Kotlin/dokka@v1.8.10...v1.8.20)

---
updated-dependencies:
- dependency-name: org.jetbrains.dokka:dokka-maven-plugin
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

pom.xml

@@ -25,7 +25,7 @@
         <flatten-plugin.version>1.3.0</flatten-plugin.version>
         <license-plugin.version>4.1</license-plugin.version>
         <git-commit-id-plugin.version>4.9.10</git-commit-id-plugin.version>
-        <dokka-plugin.version>1.8.10</dokka-plugin.version>
+        <dokka-plugin.version>1.8.20</dokka-plugin.version>
     </properties>
 
     <name>Skraper</name>