1. fix all checkstyle warning
2. change all checkstyle rules to error
3. remove some java doc rules
a. RequireEmptyLineBeforeBlockTagGroup
b. JavadocStyle
c. JavadocParagraph
4. suppress some rules for old codes
a. all java doc rules only affect on Nereids
b. DeclarationOrder only affect on Nereids
c. OverloadMethodsDeclarationOrder only affect on Nereids
d. VariableDeclarationUsageDistance only affect on Nereids
e. suppress OneTopLevelClass on org/apache/doris/load/loadv2/dpp/ColumnParser.java
f. suppress OneTopLevelClass on org/apache/doris/load/loadv2/dpp/SparkRDDAggregator.java
g. suppress LineLength on org/apache/doris/catalog/FunctionSet.java
h. suppress LineLength on org/apache/doris/common/ErrorCode.java
In order to cooperate with Doris's successful graduation from Apache, the Doris official website also needs a new look
and more powerful feature, so we decided to redesign the Doris official website.
The code and documents of the new official website are included in this PR.
Since the new website is completely rewritten, the content and structure of the project are different from the previous one.
In particular, the directory structure of documents has changed, and the number of documents is large, so the number of
files in this PR is very large.
In the old website，all English documents are in the en/ directory, and Chinese documents in the zh-CN/ directory,
but in the new website，the documents are split into multiple directories according to the nav.
The document's directory structure changes as follows：
```
docs (old website)
| |—— .vuepress (library)
| |—— en
| | |—— admin-manual
│ │ |—— advanced
| | |—— article
| | |—— benchmark
| | |—— case-user
| | |—— community
| | |—— data-operate
| | |—— data-table
| | |—— design
| | |—— developer-guide
| | |—— downloads
| | |—— ecosystem
| | |—— faq
| | |—— get-starting
| | |—— install
| | |—— sql-manual
| | |—— summary
| | |___ README.md
| |—— zh-CN
...
docs (new website)
| |—— .vuepress (library)
| |—— en
| | |—— community (unchanged, community nav)
│ │ |—— developer (new directory, developer nav)
│ │ | |—— design (moved from en/design)
│ │ | |__ developer-guide (moved from en/developer-guide)
| | |—— docs (new directory, all children directories moved from en/, document nav)
│ │ | |—— admin-manual
│ │ | |—— advanced
│ │ | |—— benchmark
│ │ | |—— data-operate
│ │ | |—— data-table
│ │ | |—— ecosystem
│ │ | |—— faq
│ │ | |—— get-starting
│ │ | |—— install
│ │ | |—— sql-manual
│ │ | |—— summary
| | |—— downloads (unchanged, downloads nav)
| | |—— userCase (moved from en/case-user, user nav)
| | |___ README.md
| |—— zh-CN
...
```
