docs: fix broken link in what-is-jsonforms page

[AssekoudaSamtou]

When you hover and click the Getting started link at the end of the documentation homepage (Figure 1), it takes you to 404-page https://jsonforms.io/getting-started (Figure 2).

Figure 1

Figure 2

[CLAassistant]

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[sdirix]

Hi @AssekoudaSamtou, thanks for the contribution ❤️

However the issue is not in the link itself. The issue comes from the top nav bar not appending the trailing slash, e.g. when you append the trailing slash yourself in the Browser or click on "What is JSON Forms?" then the link works.

I think we need to adjust these to entries here to specify a trailing slash