Auto merge of #22704 - learning:learning-patch-windows-troubleshooting, r=paulrouget

Add Windows troubleshooting

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Add Windows troubleshooting, about mach cannot run on a case-sensitive file system on Windows 10 v1803+

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- [X] `./mach build -d` does not report any errors
- [X] `./mach test-tidy` does not report any errors
- [X] These changes do not require tests because it just some text for `README.md`

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README.md

@@ -249,6 +249,10 @@ linker = "lld-link.exe"
 > 2. `cd to/the/path/servo`
 > 3. `python mach build -d`
 
+> If you got the error `Cannot run mach in a path on a case-sensitive file system on Windows`:
+> 1. Open Command Prompt or PowerShell as administrator.
+> 2. Disable case-sensitive for servo path, `fsutil.exe file SetCaseSensitiveInfo X:\path\to\servo disable`
+
 #### Cross-compilation for Android
 
 Run `./mach bootstrap-android --build` to get Android-specific tools. See wiki for