renovate PRS should be more self explanatory

We should update our renovate to add information to it's PRs

- why this PR is happening and what you should do before merging it
- we should keep up to date with dependency changes for security reasons
- but we should also be wary of updates that are from non-official repos

Also - because we suppress updates to things managed by copier template we can manage much of this by being careful about releases to copier template.
- @coretl and I discussed this and came to the conclusion that all incremental updates to copier template should be done as beta releases, except:
- if there is a critical vulnerability fix
- A periodic release, once a year or some other period to be decided

首先定位 Renovate 設定，並檢視目前如何抑制 dependency 和 copier-template 更新。定義產生的 PRs 應如何說明其目的、合併前檢查、安全價值以及 repository 來源，接著記錄或編碼針對 copier-template 更新所達成的 beta-release 與定期 release 政策。完成表示行為符合所列政策，包括重大漏洞例外。

由索引模型根據 Issue 內容生成。