Add JetBrains Gateway download "ready page"

[loujaybee]

Currently, when a user sets up their JetBrains IDE, they are presented with a Code With Me splash page (Figure 1), which instructs the user of the instructions to setup JetBrains using the Code With Me download. With the new solution where Code With Me is removed, and the user does not have the gateway application installed, the redirect will not work, and the user should be prompted to download gateway. Options: Directly link the gateway asset, link to the JetBrains toolbox, or link to our documentation where there are instructions on how to perform the gateway download. Also, see how this UX is already implemented in JetBrains spaces (figure 2).

Figure 1	Figure 2

[loujaybee]

Let me know if you have thoughts or feedback on this @gtsiolis from a UI/UX point of view ! 🙏

[akosyakov]

How can I make following nicer?

cc @loujaybee @gtsiolis

I tried to make it narrower but it still looks weird:

[gtsiolis]

@akosyakov I've posted a proposal on how this could look like in #7711 (review) and a suggestion to consolidate these instructions for all IDEs in #7711 (comment).

[loujaybee]

Looks like this will be closed with: #7711 (review)