doc(ditamap): Updated ditamap to incluse swift.md.
<topicref href="packagemgrs/pnpm.md" format="markdown"/>
<topicref href="packagemgrs/python.md" format="markdown"/>
<topicref href="packagemgrs/sbt.md" format="markdown"/>
+ <topicref href="packagemgrs/swift.md" format="markdown"/>
<topicref href="packagemgrs/yarn.md" format="markdown"/>
<topicref href="packagemgrs/yocto-bitbake.md" format="markdown"/>
</topicref>
