dsh-basic-office: DSH Office File Read and Write Plugin

`dsh-basic-office` is an office file read and write plugin designed specifically for DSH sessions, aiming to solve the issue where native text tools cannot directly process binary formats such as PDF, DOCX, XLSX, and PPTX. This plugin is based on the MIT License and requires Node.js version 20 or higher. It primarily offers two core functions: first, reading common office documents by supporting the extraction of text and table data from PDF, Word, Excel, and PPT; and second, generating various office files, including Word, Excel, PPT, PDF, and CSV files with styles and tables. After installation, the DSH Web service must be restarted, allowing users to execute read or generation tasks via natural language instructions. The plugin strictly adheres to DSH's security policies, including sandbox constraints and write protection.