Show if a module/package is adoptable

[nichtich]

As suggested by brian d foy the PAUSE user ADOPTME marks a module as available for adoptions. By now more than 180 modules are marked this way. If this information is visible at metacpan, it would both help users and possible adopters, and encourage other authors to mark their unwanted modules this way.

[oalders]

We just need to have 06perms.txt indexed in order to do this.

[ranguard]

Moved to wish list: https://github.com/CPAN-API/cpan-api/wiki/Wishlist - under Index 06perms