[examples] Added few vrf examples following #PR59

[frederic-loui]

Added few examples following VRF PR-59 corresponding to vrf manipulation primitives.

Question:
Is there a better way to fetch table_id using vrf name rather than "crawling LinkAttributes->LinkInfo->InfoData->InfoVrf->TableId ?

Anyhow, many thanks for your awesome work on rust-netlink !

[cathay4t]

Added few examples following VRF PR-59 corresponding to vrf manipulation primitives.

Question: Is there a better way to fetch table_id using vrf name rather than "crawling LinkAttributes->LinkInfo->InfoData->InfoVrf->TableId ?

This is the only way for using rtnetlink directly, I was hoping people creating crate over rtnetlink for their own use case.
I have a project https://github.com/nispor/nispor doing some data abstracting, not sure fit your need or not.

Meanwhile, I am wondering why people create PR adding examples codes which seems transparent to me, any reason we are bloating the example folder?