Umbrella Issue for KubeEdge Documentation Improvement

[Shelley-BaoYue]

Umbrella Issue for KubeEdge Documentation Improvement

[wbc6080]

add the introduction of Mapper framework and DMI
add the introduction of how to manage devices
/assign @wbc6080

[zhuyaguang]

Installing KubeEdge with Keadm ，I'm very interested in this area，I am using keadm recently and hope to add configuration for CNI plug-in.

[Shelley-BaoYue]

Installing KubeEdge with Keadm ，I'm very interested in this area，I am using keadm recently and hope to add configuration for CNI plug-in.

Sorry for the delayed response. Thank you for your involvement. I will update this issue and add your name. You can start participating directly. Feel free if you have any questions.

[wbc6080]

I have add docs about Mapper and device api at Core Concept in #475 #472 , and add docs about DMI and Mapper Framework in #471 #475 @Shelley-BaoYue

[Shelley-BaoYue]

I have add docs about Mapper and device api at Core Concept in #475 #472 , and add docs about DMI and Mapper Framework in #471 #475 @Shelley-BaoYue

Thanks for your contributions! I have updated the issue status.