Add introduction paragraph for AOT architecture diagram.
Add introduction paragraph for AOT architecture diagram.

russellhadley/llilc,BruceForstall/llilc,JosephTremoulet/llilc,dotnet/llilc,AndyAyersMS/llilc,dkorolev/llilc,pgavlin/llilc,pgavlin/llilc,richardlford/llilc,mmitche/llilc,tempbottle/llilc,marksantos/llilc,manu-silicon/llilc,adiaaida/llilc,JosephTremoulet/llilc,mmitche/llilc,libengu/llilc,AndyAyersMS/llilc,libengu/llilc,erozenfeld/llilc,dkorolev/llilc,russellhadley/llilc,erozenfeld/llilc,libengu/llilc,russellhadley/llilc,tempbottle/llilc,adiaaida/llilc,BruceForstall/llilc,marksantos/llilc,tempbottle/llilc,erozenfeld/llilc,kyulee1/llilcjit,swaroop-sridhar/llilc,russellhadley/llilc-original,russellhadley/llilc-original,richardlford/llilc,richardlford/llilc,kyulee1/llilcjit,pgavlin/llilc,russellhadley/llilc-original,dotnet/llilc,kyulee1/llilcjit,russellhadley/llilc-original,mmitche/llilc,manu-silicon/llilc,swaroop-sridhar/llilc,adiaaida/llilc,erozenfeld/llilc,libengu/llilc,JosephTremoulet/llilc,swaroop-sridhar/llilc,dotnet/llilc,BruceForstall/llilc,marksantos/llilc,mmitche/llilc,AndyAyersMS/llilc,manu-silicon/llilc,dkorolev/llilc