Add render fail warning - Close the pdf file if it is open

[jaepil-choi]

The current render fail warning is:

An error occurred:

RenderCV's built-in TinyTeX binaries couldn't render this LaTeX file into a PDF. This could be caused by one of two reasons:

1- The theme templates might have been updated in a way RenderCV's TinyTeX cannot render. RenderCV's TinyTeX is minified to keep the package size small. As a result, it doesn't function like a general-purpose LaTeX
distribution.
2- Special characters, like Greek or Chinese letters, that are not compatible with the fonts used or RenderCV's TinyTeX might have been used.

However, this issue can be resolved by using your own LaTeX distribution instead of the built-in TinyTeX. This can be done with the '--use-local-latex-command' option, as shown below:

rendercv render --use-local-latex-command lualatex John_Doe_CV.yaml

If you ensure that the generated LaTeX file can be compiled by your local LaTeX distribution, RenderCV will work successfully. You can debug the generated LaTeX file in your LaTeX editor to resolve any bugs. Then, you can
start using RenderCV with your local LaTeX distribution.

If you can't solve the problem, please open an issue on GitHub.

Please add

3 - Close the output PDF file if it is open

I thought the rendering was failing because of yaml format & unsupported character issue.

It was actually due to the open file that prevented rendercv from overwriting it.

[github-actions]

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