Updated docs

Author: cmaglie

Diff for: docs/UPGRADING.md

@@ -4,6 +4,38 @@ Here you can find a list of migration guides to handle breaking changes between
 
 ## 0.29.0
 
+### Removed gRPC API: `cc.arduino.cli.commands.v1.UpdateCoreLibrariesIndex`, `Outdated`, and `Upgrade`
+
+The following gRPC API have been removed:
+
+- `cc.arduino.cli.commands.v1.UpdateCoreLibrariesIndex`: you can use the already available gRPC methods `UpdateIndex`
+  and `UpdateLibrariesIndex` to perform the same tasks.
+- `cc.arduino.cli.commands.v1.Outdated`: you can use the already available gRPC methods `PlatformList` and `LibraryList`
+  to perform the same tasks.
+- `cc.arduino.cli.commands.v1.Upgrade`: you can use the already available gRPC methods `PlatformUpgrade` and
+  `LibraryUpgrade` to perform the same tasks.
+
+The golang API implementation of the same functions has been removed as well, so the following function are no more
+available:
+
+```
+github.com/arduino/arduino-cli/commands.UpdateCoreLibrariesIndex(...)
+github.com/arduino/arduino-cli/commands/outdated.Outdated(...)
+github.com/arduino/arduino-cli/commands/upgrade.Upgrade(...)
+```
+
+you can use the following functions as a replacement to do the same tasks:
+
+```
+github.com/arduino/arduino-cli/commands.UpdateLibrariesIndex(...)
+github.com/arduino/arduino-cli/commands.UpdateIndex(...)
+github.com/arduino/arduino-cli/commands/core.GetPlatforms(...)
+github.com/arduino/arduino-cli/commands/lib.LibraryList(...)
+github.com/arduino/arduino-cli/commands/lib.LibraryUpgrade(...)
+github.com/arduino/arduino-cli/commands/lib.LibraryUpgradeAll(...)
+github.com/arduino/arduino-cli/commands/core.PlatformUpgrade(...)
+```
+
 ### Changes in golang functions `github.com/arduino/arduino-cli/cli/instance.Init` and `InitWithProfile`
 
 The following functions: