web: profile page — repositories first, contribution grid labels, no repeated identity #225

Review items P01 to P03, out of scope for #218:

• P01: featured repositories above or beside the biography, not below it and the contribution grid.
• P02: month labels and an intensity legend on the contribution grid, plus a one-line textual summary.
• P03: stop repeating website, interests and identity in both the profile header and the biography where the header already shows them; the biography text stays the user's.