docs: add linux arm64 download link to manual installation steps (#574)

Author: zimeg

Makefile

@@ -90,7 +90,8 @@ rc:
 	./bin/slack docgen ./docs/reference --skip-update
 	sed -i.bak -E "s#slack_cli_[0-9]+\.[0-9]+\.[0-9]+_macOS_arm64\.tar\.gz#slack_cli_$(RELEASE_VERSION)_macOS_arm64.tar.gz#" docs/guides/installing-the-slack-cli-for-mac-and-linux.md
 	sed -i.bak -E "s#slack_cli_[0-9]+\.[0-9]+\.[0-9]+_macOS_amd64\.tar\.gz#slack_cli_$(RELEASE_VERSION)_macOS_amd64.tar.gz#" docs/guides/installing-the-slack-cli-for-mac-and-linux.md
-	sed -i.bak -E "s#slack_cli_[0-9]+\.[0-9]+\.[0-9]+_linux_64-bit\.tar\.gz#slack_cli_$(RELEASE_VERSION)_linux_64-bit.tar.gz#" docs/guides/installing-the-slack-cli-for-mac-and-linux.md
+	sed -i.bak -E "s#slack_cli_[0-9]+\.[0-9]+\.[0-9]+_linux_amd64\.tar\.gz#slack_cli_$(RELEASE_VERSION)_linux_amd64.tar.gz#" docs/guides/installing-the-slack-cli-for-mac-and-linux.md
+	sed -i.bak -E "s#slack_cli_[0-9]+\.[0-9]+\.[0-9]+_linux_arm64\.tar\.gz#slack_cli_$(RELEASE_VERSION)_linux_arm64.tar.gz#" docs/guides/installing-the-slack-cli-for-mac-and-linux.md
 	sed -i.bak -E "s#slack_cli_[0-9]+\.[0-9]+\.[0-9]+_windows_64-bit\.zip#slack_cli_$(RELEASE_VERSION)_windows_64-bit.zip#" docs/guides/installing-the-slack-cli-for-windows.md
 	sed -i.bak -E "s/Using slack v[0-9]+\.[0-9]+\.[0-9]+/Using slack v$(RELEASE_VERSION)/" docs/guides/installing-the-slack-cli-for-mac-and-linux.md
 	sed -i.bak -E "s/Using slack v[0-9]+\.[0-9]+\.[0-9]+/Using slack v$(RELEASE_VERSION)/" docs/guides/installing-the-slack-cli-for-windows.md

docs/guides/installing-the-slack-cli-for-mac-and-linux.md

@@ -103,7 +103,9 @@ Manual installation allows you to customize certain paths used when installing t
 
 🍏 🪨 [**Download for macOS Intel (.tar.gz)**](https://downloads.slack-edge.com/slack-cli/slack_cli_4.3.0_macOS_amd64.tar.gz)
 
-🐧 💾 [**Download for Linux (.tar.gz)**](https://downloads.slack-edge.com/slack-cli/slack_cli_4.3.0_linux_64-bit.tar.gz)
+🐧 💾 [**Download for Linux x86_64 (.tar.gz)**](https://downloads.slack-edge.com/slack-cli/slack_cli_4.3.0_linux_amd64.tar.gz)
+
+🐧 💪 [**Download for Linux ARM64 (.tar.gz)**](https://downloads.slack-edge.com/slack-cli/slack_cli_4.3.0_linux_arm64.tar.gz)
 
 **3\. Add the** `slack` **CLI to your path.**