ci: add lychee to check external links

.github/workflows/lychee.yml

@@ -0,0 +1,28 @@
+name: lychee
+
+on:
+  push:
+    branches:
+      - master
+  schedule:
+    - cron: '0 0 1 * *'
+
+jobs:
+  links:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v3
+
+    - name: Link Checker
+      uses: lycheeverse/lychee-action@master
+      env:
+        GITHUB_TOKEN: ${{secrets.GITHUB_TOKEN}}
+      with:
+        args: '--verbose --max-retries 4 --no-progress "**/*.md"'
+
+    - name: Create Issue From File
+      uses: peter-evans/create-issue-from-file@v2
+      with:
+        title: Link Checker Report
+        content-filepath: ./lychee/out.md
+        labels: automated issue

.lycheeignore

@@ -0,0 +1,4 @@
+https://talk.nervos.org/
+https://discord.gg/8cWtA9uJR5
+/@[^/]+
+wancencen@cryptape.com

rfcs/0003-ckb-vm/0003-ckb-vm.md

@@ -97,7 +97,7 @@ CKB only defines the low level virtual machine. In theory, any languages with RI
 * CKB can leverage standard riscv-gcc, riscv-llvm or even upstream gcc/llvm for C/C++ contract development. Executables emitted by those compilers can be directly used as CKB contracts.
 * C-based Bitcoin or Ethereum VM can also be compiled into RISC-V binaries as common cells, contracts can then load those common cells to run Bitcoin or Ethereum compatible contracts.
 * Higher-level language VMs, such as [duktape](http://duktape.org/) or [mruby](https://github.com/mruby/mruby) can also be compiled and loaded to run contracts running by JavaScript or Ruby
-* [Rust](https://github.com/riscv-rust/rust) can also be used to write contracts with recent development in this space
+* [Rust](https://github.com/riscv-rust/riscv-rust-quickstart) can also be used to write contracts with recent development in this space
 
 ## Runtime Cost
 

rfcs/0003-ckb-vm/0003-ckb-vm.zh.md

@@ -70,7 +70,7 @@ CKB 核心只定义了底层的虚拟机模型，理论上任何提供了 RISC-V
 * CKB 可以直接使用标准的 riscv-gcc 以及 riscv-llvm 以 C/C++ 语言来进行开发。编译后的可执行文件可以直接作为 CKB 的合约来使用
 * 与此相应的，可以将 C 实现的 Bitcoin 以及 Ethereum VM 编译成 RISC-V 二进制代码，保存在公共 Cell 中，然后在合约中引用公共 Cell 来运行 Bitcoin 或者 Ethereum 的合约
 * 其他的高级语言 VM 如 [duktape](http://duktape.org/) 及 [mruby](https://github.com/mruby/mruby) 在编译后，也可以用来相应的运行 JavaScript 或者 Ruby 编写的合约
-* 相应的也可以使用 [Rust](https://github.com/riscv-rust/rust) 作为实现语言来编写合约
+* 相应的也可以使用 [Rust](https://github.com/riscv-rust/riscv-rust-quickstart) 作为实现语言来编写合约
 
 ## Runtime Cost
 

rfcs/0005-priviledged-mode/0005-priviledged-mode.md

@@ -24,7 +24,7 @@ Notice privileged architecture here is an opt-in feature that is closed by defau
 
 ## Privileged mode support via CSR instructions
 
-To ensure maximum compatibility, we will use the exact instructions and workflows defined in the [RISC-V spec](https://riscv.org/specifications/privileged-isa/) to implement privilege mode support here:
+To ensure maximum compatibility, we will use the exact instructions and workflows defined in the [RISC-V spec](https://riscv.org/technical/specifications/privileged-isa/) to implement privilege mode support here:
 
 * First, CSR instructions as defined in RISC-V will be implemented in CKB VM to implement read/write on control and status registers(CSR).
 * For simplicity reasons, we might not implement every control and status register as defined in RISC-V spec. For now, we are planning to implement `Supervisor Trap Vector Base Address Register(stvec)` and any other register that might be used in the trap phase. As documented in the spec, reading/writing other registers will result in illegal instruction exception, it's up to contract writer how they want to handle this.

rfcs/0005-priviledged-mode/0005-priviledged-mode.zh.md

@@ -24,7 +24,7 @@ Created: 2018-11-26
 
 ## 基于 CSR 指令的特权模式支持
 
-为尽最大可能确保兼容性，我们会用 [RISC-V 标准](https://riscv.org/specifications/privileged-isa/) 中定义的指令以及流程来实现特权指令支持：
+为尽最大可能确保兼容性，我们会用 [RISC-V 标准](https://riscv.org/technical/specifications/privileged-isa/) 中定义的指令以及流程来实现特权指令支持：
 
 * 首先，我们会实现 RISC-V 标准中定义的 CSR 指令，用于读写控制与状态寄存器 (CSR)。
 * 出于简化实现的考虑，我们不会实现 RISC-V 中定义的每一个控制与状态寄存器。目前为止，我们只计划实现 `Supervisor Trap Vector Base Address Register(stvec)` 以及其他在 trap 阶段会被用到的寄存器。在 CKB VM 中读写其他寄存器会参照 spec 中的定义，抛出违法指令的异常，合约开发者可以自行决定如何处理异常。