[Improvement] Unification of usage specifications for representing Linkis installation directories

[casionone]

A different representation has been found in the documentation that currently represents the installation and deployment directory of Linkis:

${InstallPath}/conf/*properties
${linkis_home}/conf
${LINKIS_HOME}/lib/linkis-engineconn-plugins

It is recommended to keep it unified and use ${LINKIS_HOME}?

---

当前表示Linkis的安装部署目录 文档中已发现有不同的表示方式:

${InstallPath}/conf/*properties
${linkis_home}/conf
${LINKIS_HOME}/lib/linkis-engineconn-plugins

建议保持统一 ，统一使用${LINKIS_HOME}?