#### What type of PR is this?
/kind documentation
#### What this PR does / why we need it:
Bump image tag in docker command.
#### Does this PR introduce a user-facing change?
```release-note
None
```
#### What type of PR is this?
/kind documentation
#### What this PR does / why we need it:
The README.md is out of date due to [2.0.0-alpha.2](https://github.com/halo-dev/halo/releases/tag/v2.0.0-alpha.2) released.
#### Does this PR introduce a user-facing change?
```release-note
None
```
#### What type of PR is this?
/kind documentation
/milestone 2.0
#### What this PR does / why we need it:
更新 README,提供 Halo 2.0 的演示环境信息。
#### Special notes for your reviewer:
/cc @halo-dev/sig-halo
#### Does this PR introduce a user-facing change?
```release-note
None
```
#### What type of PR is this?
/kind documentation
/milestone 2.0
#### What this PR does / why we need it:
因为目前暂时没有提供 JAR 包,所以移除 README 有关使用 JAR 包运行的文档。
#### Special notes for your reviewer:
/cc @halo-dev/sig-halo
#### Does this PR introduce a user-facing change?
```release-note
None
```
#### What type of PR is this?
/kind documentation
/milestone 2.0
#### What this PR does / why we need it:
更新 README。
See https://github.com/halo-dev/halo/issues/2410 for more
#### Special notes for your reviewer:
/hold
#### Does this PR introduce a user-facing change?
```release-note
None
```