Umbrella Issue: A part of docs has some issues, is inconsistent, and should be improved

[1Shubham7]

PRs related to this issue:

1. https://github.com/kubeedge/website/pull/544
2. https://github.com/kubeedge/website/pull/558
3. https://github.com/kubeedge/website/pull/543
4. https://github.com/kubeedge/website/pull/559
5. https://github.com/kubeedge/website/pull/564
6. https://github.com/kubeedge/website/pull/565
7. https://github.com/kubeedge/website/pull/567
8. https://github.com/kubeedge/website/pull/568

Is your feature request related to a problem? Please describe.

There are inconsistencies, Grammatical mistakes and misspells in the current documentation. Apart from that it can generally also be improved to make it easier to understand.

• I see some inconsistencies in the docs. For example: at https://kubeedge.io/docs/setup/install-with-keadm/ , keadm is sometimes referred as Keadm and sometimes as keadm

• Grammatical errors: (link) Need super user rights (or root rights) to run. -> It should be Needs.

And sentences are not phrased in a proper manner (In my opinion). for example:

Keadm is used to install the cloud and edge components of KubeEdge. It is not responsible for installing K8s and runtime.

Please refer [kubernetes-compatibility](https://github.com/kubeedge/kubeedge#kubernetes-compatibility) to get **Kubernetes compatibility** and determine what version of Kubernetes would be installed.

## Limitation

- Need super user rights (or root rights) to run.

can be rephrased as :

Keadm is used to install the cloud and edge components of KubeEdge. It does not handle the installation of K8s and its runtime environment.

Please refer to [kubernetes-compatibility](https://github.com/kubeedge/kubeedge#kubernetes-compatibility) documentation to check **Kubernetes compatibility** and ascertain the Kubernetes version to be installed.

## Limitation

- Needs super user rights (or root rights) to run.

Describe the solution you'd like

There are more such examples I am finding as I keep of reading more documentation. I can rephrase at least some part of docs if the maintainers are up for it.

Describe alternatives you've considered Alternative would be to at least fix grammatical mistakes and inconsistencies.

[fujitatomoya]

@1Shubham7 i believe that is really nice to address your points. i am happy to help review !!!

[1Shubham7]

@fujitatomoya @wbc6080 @fisherxu @Shelley-BaoYue , I have made some PRs under this issue, please give your suggestions whenever you have time.