Update sketch name specifications in docs

Author: MatteoPologruto

Diff for: docs/UPGRADING.md

@@ -2,6 +2,15 @@
 
 Here you can find a list of migration guides to handle breaking changes between releases of the CLI.
 
+## 0.34.0
+
+### Updated sketch name specifications
+
+[Sketch name specifications](https://arduino.github.io/arduino-cli/dev/sketch-specification) have been updated to
+achieve cross-platform compatibility.
+
+Existing sketch names violating the new constraint need to be updated.
+
 ## 0.33.0
 
 ### gRPC `cc.arduino.cli.commands.v1.Compile` command now return expanded build_properties by default.

Diff for: docs/sketch-specification.md

@@ -7,7 +7,9 @@ The programs that run on Arduino boards are called "sketches". This term was inh
 
 The sketch root folder name and code file names must start with a basic letter (`A`-`Z` or `a`-`z`), number (`0`-`9`)
 [<sup>1</sup>](#leading-number-note), or underscore (`_`) [<sup>2</sup>](#leading-underscore-note) followed by basic
-letters, numbers, underscores, dots (`.`) and dashes (`-`). The maximum length is 63 characters.
+letters, numbers, underscores, dots (`.`) and dashes (`-`). The maximum length is 63 characters. The sketch name cannot
+end with a dot (`.`) and cannot be a
+[reserved name](https://learn.microsoft.com/en-us/windows/win32/fileio/naming-a-file#naming-conventions).
 
 <a id="leading-number-note"></a> <sup>1</sup> Supported from Arduino IDE 1.8.4. <br />
 <a id="leading-underscore-note"></a> <sup>2</sup> Supported in all versions except Arduino IDE 2.0.4/Arduino CLI