add link to SSIM description on Wikipedia
add link to SSIM description on Wikipedia

+ a brief description of LSIM

Change-Id: I4344f3e3b28d8bc4109b729dec9000e9c8fcbdbb

ericmckean/webm.libwebp,ericmckean/webm.libwebp,ttyangf/libwebp,kim42083/webm.libwebp,altogother/webm.libwebp,webmproject/libwebp,webmproject/libwebp,altogother/webm.libwebp,ttyangf/libwebp,yohunl/libwebp,PKRoma/libwebp,iniwf/webm.libwebp,Acidburn0zzz/webm.libwebp,PKRoma/libwebp,matanbs/webm.libwebp,Suvarna1488/webm.libwebp,kalli123/webm.libwebp,Tekserve/libwebp,kalli123/webm.libwebp,comoyo/gonzo-libwebp,kim42083/webm.libwebp,redengineer/libwebp,appunite/libwebp,kalli123/webm.libwebp,cysp/libwebp,kleopatra999/webm.libwebp,iniwf/webm.libwebp,gshORTON/webm.libwebp,Aexyn/libwebp,jacklicn/libwebp,gshORTON/webm.libwebp,PKRoma/libwebp,gshORTON/webm.libwebp,ya7lelkom/libwebp,comoyo/gonzo-libwebp,gshORTON/webm.libwebp,matanbs/webm.libwebp,Distrotech/libwebp,jacklicn/libwebp,abwiz0086/webm.libwebp,comoyo/gonzo-libwebp,jiehu5114/libwebp,kleopatra999/webm.libwebp,rxl194/libwebp,webmproject/libwebp,matanbs/webm.libwebp,ttyangf/libwebp,comoyo/gonzo-libwebp,altogother/webm.libwebp,altogother/webm.libwebp,kalli123/webm.libwebp,keane83/BLE_IM,Maria1099/webm.libwebp,reimaginemedia/webm.libwebp,appunite/libwebp,reimaginemedia/webm.libwebp,reimaginemedia/webm.libwebp,jiehu5114/libwebp,kim42083/webm.libwebp,imazen/libwebp,dumganhar/libwebp,matanbs/webm.libwebp,PKRoma/libwebp,kleopatra999/webm.libwebp,imazen/libwebp,zofuthan/libwebp,ttyangf/libwebp,kleopatra999/webm.libwebp,zofuthan/libwebp,ericmckean/webm.libwebp,keane83/BLE_IM,ya7lelkom/libwebp,ya7lelkom/libwebp,jiehu5114/libwebp,imazen/libwebp,iniwf/webm.libwebp,kleopatra999/webm.libwebp,jacklicn/libwebp,kim42083/webm.libwebp,rxl194/libwebp,Aexyn/libwebp,comoyo/gonzo-libwebp,kalli123/webm.libwebp,Distrotech/libwebp,webmproject/libwebp,abwiz0086/webm.libwebp,abwiz0086/webm.libwebp,cysp/libwebp,jacklicn/libwebp,iniwf/webm.libwebp,Suvarna1488/webm.libwebp,zofuthan/libwebp,imazen/libwebp,appunite/libwebp,yohunl/libwebp,jiehu5114/libwebp,yohunl/libwebp,redengineer/libwebp,Suvarna1488/webm.libwebp,redengineer/libwebp,rxl194/libwebp,Tekserve/libwebp,ericmckean/webm.libwebp,cysp/libwebp,gshORTON/webm.libwebp,Suvarna1488/webm.libwebp,Suvarna1488/webm.libwebp,cysp/libwebp,Aexyn/libwebp,ya7lelkom/libwebp,Distrotech/libwebp,zofuthan/libwebp,ttyangf/libwebp,zofuthan/libwebp,kim42083/webm.libwebp,yohunl/libwebp,redengineer/libwebp,comoyo/gonzo-libwebp,Aexyn/libwebp,abwiz0086/webm.libwebp,jiehu5114/libwebp,Acidburn0zzz/webm.libwebp,keane83/BLE_IM,comoyo/gonzo-libwebp,Maria1099/webm.libwebp,redengineer/libwebp,yohunl/libwebp,appunite/libwebp,dumganhar/libwebp,imazen/libwebp,Acidburn0zzz/webm.libwebp,Tekserve/libwebp,ericmckean/webm.libwebp,appunite/libwebp,iniwf/webm.libwebp,matanbs/webm.libwebp,Maria1099/webm.libwebp,reimaginemedia/webm.libwebp,ya7lelkom/libwebp,webmproject/libwebp,Maria1099/webm.libwebp,dumganhar/libwebp,PKRoma/libwebp,Acidburn0zzz/webm.libwebp,jacklicn/libwebp,Aexyn/libwebp,keane83/BLE_IM,rxl194/libwebp,altogother/webm.libwebp,PKRoma/libwebp,Acidburn0zzz/webm.libwebp,Maria1099/webm.libwebp,reimaginemedia/webm.libwebp,rxl194/libwebp,appunite/libwebp,keane83/BLE_IM,abwiz0086/webm.libwebp,Tekserve/libwebp