ci: drop AppVeyor and its badge

.appveyor.yml

@@ -1,50 +0,0 @@
-build: false
-install:
-  # Terminate early unless building either a tag or a PR.
-  - if "%APPVEYOR_REPO_TAG%" == "false" if not "%APPVEYOR_REPO_BRANCH%" == "master" appveyor exit
-
-  # Install rust
-  - appveyor DownloadFile https://win.rustup.rs/ -FileName rustup-init.exe
-  - IF "%PLATFORM%" == "x86" rustup-init -y --default-toolchain stable --default-host i686-pc-windows-msvc
-  - IF "%PLATFORM%" == "x64" rustup-init -y --default-toolchain stable --default-host x86_64-pc-windows-msvc
-  - set PATH=%PATH%;C:\Users\appveyor\.cargo\bin
-  - rustc -vV
-  - cargo -vV
-
-  # Install dependencies
-  - git submodule update --init
-
-platform:
-  - x64
-  - x86
-
-test_script:
-  # Fetch and regenerate the fixture parsers
-  - script\fetch-fixtures.cmd
-  - cargo build --release
-  - script\generate-fixtures.cmd
-
-  # Run tests
-  - script\test.cmd
-  - script\benchmark.cmd
-
-before_deploy:
-  - move target\release\tree-sitter.exe tree-sitter.exe
-  - 7z a -tgzip tree-sitter-windows-%PLATFORM%.gz tree-sitter.exe
-  - appveyor PushArtifact tree-sitter-windows-%PLATFORM%.gz
-
-deploy:
-  description: ''
-  provider: GitHub
-  auth_token:
-    secure: VC9ntV5+inKoNteZyLQksKzWMKXF46P+Jx3JHKVSfF+o1rWtZn2iIHAVsQv5LaUi
-  artifact: /tree-sitter-windows-.*/
-  draft: true
-  force_update: true
-  on:
-    APPVEYOR_REPO_TAG: true
-
-cache:
-  - target
-  - test\fixtures\grammars
-  - C:\Users\appveyor\.cargo

README.md

@@ -1,7 +1,6 @@
 # tree-sitter
 
 [![Build Status](https://github.com/tree-sitter/tree-sitter/workflows/CI/badge.svg)](https://github.com/tree-sitter/tree-sitter/actions)
-[![Build status](https://ci.appveyor.com/api/projects/status/vtmbd6i92e97l55w/branch/master?svg=true)](https://ci.appveyor.com/project/maxbrunsfeld/tree-sitter/branch/master)
 [![DOI](https://zenodo.org/badge/14164618.svg)](https://zenodo.org/badge/latestdoi/14164618)
 
 Tree-sitter is a parser generator tool and an incremental parsing library. It can build a concrete syntax tree for a source file and efficiently update the syntax tree as the source file is edited. Tree-sitter aims to be: