[documentation] Related modules on project page description for now

[Charlie Lowe]

Kieran Lal wrote:
> 
> In that case Flexinode should probably have Flexisearch.  How about  we 
> discuss these changes on the docs list first before we start  editing?  
> I am eager to improve things but want to evolve the overall  guidelines 
> and not remove and expected functionality.

Good point. However, doesn't Flexinode work without Flexisearch? It does 
in 4.6 or has this changed? If so, Flexinode would not need to list 
Flexisearch, although Flexisearch would need Flexinode.