feat: 纯文本简历按版本拆分并新增 /txt 选择页

- resume/index.txt 与 soe/index.txt 分别对应主简历与央国企简历纯文本
- /txt 改为选择页，/txt/resume 与 /txt/soe 提供对应纯文本
- 删除过时的根目录 resume.txt，Dockerfile 与 README 同步更新

Co-Authored-By: Claude Code <noreply@anthropic.com>

Dockerfile

@@ -7,8 +7,8 @@ COPY nginx.conf /etc/nginx/conf.d/default.conf
 COPY css/ /usr/share/nginx/html/css/
 COPY img/ /usr/share/nginx/html/img/
 COPY resume/ /usr/share/nginx/html/resume/
-COPY resume.txt /usr/share/nginx/html/resume.txt
 COPY other/ /usr/share/nginx/html/other/
+COPY txt/ /usr/share/nginx/html/txt/
 COPY soe/ /usr/share/nginx/html/soe/
 
 # 暴露端口