Results 3 issues of Tushushu

Line 48: {base_dir, src} has been changed to [base_dir, src] @advancedxy Hi there, I am going to fix those issues later~

### Bug Description When I ran `cargo test` command, it failed with the following errors: ``` cargo test Compiling target-lexicon v0.12.4 Compiling autocfg v1.1.0 Compiling once_cell v1.13.1 Compiling proc-macro2 v1.0.43...

enhancement
documentation
needs-design

Hi there~ I am trying to use `Grafanalib` to generate Grafana dashboards programmatically. It works great, except that I need to write a `to_json` function myself, since the `Dashboard.to_json_data method`...