Add more specific GitHub issue templates

Apply suggestions from code review

Co-authored-by: Philipp Krones <hello@philkrones.com>

.github/ISSUE_TEMPLATE/blank_issue.md

@@ -0,0 +1,4 @@
+---
+name: Blank Issue
+about: Create a blank issue.
+---

.github/ISSUE_TEMPLATE/bug_report.md

@@ -0,0 +1,47 @@
+---
+name: Bug Report
+about: Create a bug report for Clippy
+labels: L-bug
+---
+<!--
+Thank you for filing a bug report! 🐛 Please provide a short summary of the bug,
+along with any information you feel relevant to replicating the bug.
+-->
+
+I tried this code:
+
+```rust
+<code>
+```
+
+I expected to see this happen: *explanation*
+
+Instead, this happened: *explanation*
+
+### Meta
+
+- `cargo clippy -V`: e.g. clippy 0.0.212 (f455e46 2020-06-20)
+- `rustc -Vv`:
+  ```
+  rustc 1.46.0-nightly (f455e46ea 2020-06-20)
+  binary: rustc
+  commit-hash: f455e46eae1a227d735091091144601b467e1565
+  commit-date: 2020-06-20
+  host: x86_64-unknown-linux-gnu
+  release: 1.46.0-nightly
+  LLVM version: 10.0
+  ```
+
+<!--
+Include a backtrace in the code block by setting `RUST_BACKTRACE=1` in your
+environment. E.g. `RUST_BACKTRACE=1 cargo clippy`.
+-->
+<details><summary>Backtrace</summary>
+  <p>
+
+  ```
+  <backtrace>
+  ```
+
+  </p>
+</details>

.github/ISSUE_TEMPLATE/config.yml

@@ -0,0 +1,5 @@
+blank_issues_enabled: true
+contact_links:
+  - name: Rust Programming Language Forum
+    url: https://users.rust-lang.org
+    about: Please ask and answer questions about Rust here.

.github/ISSUE_TEMPLATE/ice.md

@@ -0,0 +1,53 @@
+---
+name: Internal Compiler Error
+about: Create a report for an internal compiler error in Clippy.
+labels: L-bug, L-crash
+---
+<!--
+Thank you for finding an Internal Compiler Error! 🧊  If possible, try to provide
+a minimal verifiable example. You can read "Rust Bug Minimization Patterns" for
+how to create smaller examples.
+
+http://blog.pnkfx.org/blog/2019/11/18/rust-bug-minimization-patterns/
+
+-->
+
+### Code
+
+```rust
+<code>
+```
+
+### Meta
+
+- `cargo clippy -V`: e.g. clippy 0.0.212 (f455e46 2020-06-20)
+- `rustc -Vv`:
+  ```
+  rustc 1.46.0-nightly (f455e46ea 2020-06-20)
+  binary: rustc
+  commit-hash: f455e46eae1a227d735091091144601b467e1565
+  commit-date: 2020-06-20
+  host: x86_64-unknown-linux-gnu
+  release: 1.46.0-nightly
+  LLVM version: 10.0
+  ```
+
+### Error output
+
+```
+<output>
+```
+
+<!--
+Include a backtrace in the code block by setting `RUST_BACKTRACE=1` in your
+environment. E.g. `RUST_BACKTRACE=1 cargo clippy`.
+-->
+<details><summary>Backtrace</summary>
+  <p>
+
+  ```
+  <backtrace>
+  ```
+
+  </p>
+</details>

.github/ISSUE_TEMPLATE/new_lint.md

@@ -0,0 +1,35 @@
+---
+name: New lint suggestion
+about: Suggest a new Clippy lint.
+labels: L-lint
+---
+
+### What it does
+
+*What does this lint do?*
+
+### Categories (optional)
+
+- Kind: *See <https://github.com/rust-lang/rust-clippy/blob/master/README.md#clippy> for list of lint kinds*
+
+*What benefit of this lint over old code?*
+
+For example:
+- Remove bounce checking inserted by ...
+- Remove the need to duplicating/storing/typo ...
+
+### Drawbacks
+
+None.
+
+### Example
+
+```rust
+<code>
+```
+
+Could be written as:
+
+```rust
+<code>
+```

.github/PULL_REQUEST_TEMPLATE.md

@@ -28,4 +28,5 @@ Delete this line and everything above before opening your PR.
 
 ---
 
+*Please keep the line below*
 changelog: none