Set license key instructions outdated

[Herz3h]

Describe the bug According to main repository, licensekey should be set using intelephense.enter.key. You can check https://github.com/bmewburn/vscode-intelephense/blob/e9bae55e77acaae1f40b0df5f5f8b4ad052429df/package.json#L598

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Expected behavior NA

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Desktop (please complete the following information):

• OS: [e.g. iOS]
• Browser [e.g. chrome, safari]
• Version [e.g. 22]

Additional context NA