Auto merge of #8110 - xFrednet:0000-lintcheck-markdown-output, r=matthiaskrgr

Update lintcheck output to use tables and add markdown support

This PR updates changes lintcheck's output to use text tables and adds a markdown option to use Markdown links in the reports table. At first, I tried to keep the original output format, but the loading of old stats broke with the markdown option. The old format is therefore sadly incompatible with the new one. I can if requested make it in a way that the markdown output is only and optional additional output, but that would require more work for little benefit IMO.

For now, lintcheck has two output types. Here are the examples (best viewed on desktop):

<details>
<summary>`cargo lintcheck --only anyhow`</summary>

```txt
clippy 0.1.59 (460bef22a 2021-12-08)

### Reports

target/lintcheck/sources/anyhow-1.0.38/build.rs:1:null clippy::cargo_common_metadata "package `anyhow` is missing `package.keywords` metadata"
target/lintcheck/sources/anyhow-1.0.38/src/error.rs:350:5 clippy::missing_panics_doc "docs for function which may panic missing `# Panics` section"
target/lintcheck/sources/anyhow-1.0.38/src/lib.rs:1:null clippy::cargo_common_metadata "package `anyhow` is missing `package.keywords` metadata"

### Stats:

| lint                                               | count |
| -------------------------------------------------- | ----- |
| clippy::missing_panics_doc                         |     1 |
| clippy::cargo_common_metadata                      |     2 |

### ICEs:

```

</details>

<details>
<summary>`cargo lintcheck --only anyhow --markdown` (The file links only work locally)</summary>

clippy 0.1.59 (460bef22a 2021-12-08)

### Reports

| file | lint | message |
| --- | --- | --- |
| [`anyhow-1.0.38/build.rs:1:null`](../target/lintcheck/sources/anyhow-1.0.38/build.rs#L1) | `clippy::cargo_common_metadata`                    | "package `anyhow` is missing `package.keywords` metadata" |
| [`anyhow-1.0.38/src/error.rs:350:5`](../target/lintcheck/sources/anyhow-1.0.38/src/error.rs#L350) | `clippy::missing_panics_doc`                       | "docs for function which may panic missing `# Panics` section" |
| [`anyhow-1.0.38/src/lib.rs:1:null`](../target/lintcheck/sources/anyhow-1.0.38/src/lib.rs#L1) | `clippy::cargo_common_metadata`                    | "package `anyhow` is missing `package.keywords` metadata" |

### Stats:

| lint                                               | count |
| -------------------------------------------------- | ----- |
| clippy::missing_panics_doc                         |     1 |
| clippy::cargo_common_metadata                      |     2 |

### ICEs:

</details>

The table margins are so large to keep the table inline for long file names and lint names

---

changelog: none

r? `@matthiaskrgr`

0 files changed, 0 insertions, 0 deletions