After one failure to find documentation, the extension stops working

[danyalaytekin]

Visual Studio Code 1.24.0 ESDoc MDN 0.4.0 macOS 10.13.5

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If the extension ever fails to find some documentation on MDN, the extension will not try to find documentation again when a valid instruction is given. This is can be resolved by restarting VS Code.

To reproduce:

1. Type something for which documentation doesn't exist on MDN, e.g. //mdn sinon.stub;.
2. Observe that the extension responds with No documentation found about "sinon.stub".
3. Close the extension's results page.
4. Type something for which documentation does exist, e.g. //mdn array.length;.
5. Observe that the extension does not respond.

[samundrak]

Hey, thanks for the issue, I will be working on it asap :+1:

[samundrak]

3