README: add documentation about then_wrapped
README: add documentation about then_wrapped

Signed-off-by: Glauber Costa <f8b79557d19b40666ebe336545a0b6178af65685@cloudius-systems.com>

slivne/seastar,avikivity/seastar,ducthangho/imdb,tempbottle/seastar,shyamalschandra/seastar,syuu1228/seastar,stamhe/seastar,justintung/scylla,tempbottle/seastar,avikivity/scylla,leejir/seastar,acbellini/scylla,asias/scylla,syuu1228/seastar,acbellini/scylla,scylladb/scylla,scylladb/seastar,eklitzke/scylla,phonkee/scylla,capturePointer/scylla,capturePointer/scylla,linearregression/scylla,dwdm/seastar,rentongzhang/scylla,scylladb/scylla,raphaelsc/scylla,stamhe/scylla,leejir/seastar,kjniemi/seastar,linearregression/scylla,raphaelsc/seastar,scylladb/scylla-seastar,scylladb/scylla,shyamalschandra/seastar,leejir/seastar,guiquanz/scylla,bzero/seastar,koolhazz/seastar,tempbottle/seastar,xtao/seastar,flashbuckets/seastar,avikivity/scylla,eklitzke/scylla,phonkee/scylla,acbellini/seastar,wildinto/seastar,kangkot/scylla,syuu1228/seastar,wildinto/seastar,senseb/scylla,avikivity/seastar,hongliangzhao/seastar,norcimo5/seastar,anzihenry/seastar,flashbuckets/seastar,glommer/scylla,sjperkins/seastar,kjniemi/scylla,wildinto/scylla,bowlofstew/scylla,gwicke/scylla,respu/scylla,victorbriz/scylla,bowlofstew/seastar,tempbottle/scylla,ducthangho/imdb,acbellini/seastar,raphaelsc/scylla,scylladb/scylla,dwdm/scylla,wildinto/scylla,dwdm/seastar,respu/scylla,cloudius-systems/seastar,bowlofstew/scylla,chunshengster/seastar,dwdm/scylla,koolhazz/seastar,kjniemi/seastar,dreamsxin/seastar,guiquanz/scylla,duarten/scylla,tempbottle/scylla,norcimo5/seastar,raphaelsc/seastar,scylladb/seastar,koolhazz/seastar,bowlofstew/seastar,wildinto/seastar,senseb/scylla,printedheart/seastar,gwicke/scylla,capturePointer/scylla,sjperkins/seastar,aruanruan/scylla,xtao/seastar,sjperkins/seastar,wildinto/scylla,rluta/scylla,shyamalschandra/seastar,chunshengster/seastar,justintung/scylla,hongliangzhao/seastar,senseb/scylla,dreamsxin/seastar,slivne/seastar,bowlofstew/seastar,mixja/seastar,raphaelsc/scylla,mixja/seastar,rluta/scylla,printedheart/seastar,shaunstanislaus/scylla,linearregression/seastar,xtao/seastar,slivne/seastar,duarten/scylla,kangkot/scylla,bowlofstew/scylla,linearregression/seastar,linearregression/seastar,joerg84/seastar,jonathanleang/seastar,anzihenry/seastar,scylladb/scylla-seastar,cloudius-systems/seastar,aruanruan/scylla,victorbriz/scylla,flashbuckets/seastar,norcimo5/seastar,guiquanz/scylla,acbellini/scylla,ducthangho/imdb,shaunstanislaus/scylla,chunshengster/seastar,asias/scylla,bzero/seastar,rluta/scylla,stamhe/scylla,eklitzke/scylla,glommer/scylla,stamhe/scylla,dreamsxin/seastar,duarten/scylla,dwdm/scylla,joerg84/seastar,stamhe/seastar,printedheart/seastar,gwicke/scylla,respu/scylla,tempbottle/scylla,cloudius-systems/seastar,acbellini/seastar,kjniemi/scylla,avikivity/seastar,asias/scylla,rentongzhang/scylla,jonathanleang/seastar,hongliangzhao/seastar,aruanruan/scylla,jonathanleang/seastar,kjniemi/seastar,joerg84/seastar,bzero/seastar,rentongzhang/scylla,victorbriz/scylla,glommer/scylla,shaunstanislaus/scylla,scylladb/scylla-seastar,kjniemi/scylla,anzihenry/seastar,justintung/scylla,phonkee/scylla,scylladb/seastar,mixja/seastar,avikivity/scylla,kangkot/scylla,raphaelsc/seastar,stamhe/seastar,dwdm/seastar,linearregression/scylla