[WIKI] Explain how to use uBlock Origin / enable MV2 in Chrome 139-140

[I-I-IT]

Chrome 139 disables support for Manifest V2, but there is a workaround, which also works in Chrome 140.

For Chrome 139

1. Restore old flags with

chrome://flags/#temporary-unexpire-flags-m137
chrome://flags/#temporary-unexpire-flags-m138

1. Enable
   chrome://flags/#allow-legacy-mv2-extensions
2. Optionally, disable the depreciation warnings

chrome://flags/#extension-manifest-v2-deprecation-warning
chrome://flags/#extension-manifest-v2-deprecation-disabled
chrome://flags/#extension-manifest-v2-de precation-unsupported

For Chrome 140/ when upgrading to Chrome 140 (the extension will become disabled, and you will need to do the steps below to reactivate it - I am not sure if the data is wiped or not, since I don't use Chrome Canary often. Make a backup just in case).

1. Restore old flags

chrome://flags/#temporary-unexpire-flags-m138
chrome://flags/#temporary-unexpire-flags-m139

2. Enable

chrome://flags/#allow-legacy-mv2-extensions