Bump ini from 1.3.5 to 1.3.8 in /book/9-begin

Bumps [ini](https://github.com/isaacs/ini) from 1.3.5 to 1.3.8.
- [Release notes](https://github.com/isaacs/ini/releases)
- [Commits](npm/ini@v1.3.5...v1.3.8)

Signed-off-by: dependabot[bot] <[email protected]>