[doc] add pkg-config for building h2olog
[doc] add pkg-config for building h2olog

h2o/h2o,yannick/h2o,devnexen/h2o,cwyang/h2o,devnexen/h2o,cwyang/h2o,devnexen/h2o,cwyang/h2o,cwyang/h2o,h2o/h2o,h2o/h2o,devnexen/h2o,devnexen/h2o,yannick/h2o,yannick/h2o,devnexen/h2o,h2o/h2o,cwyang/h2o,devnexen/h2o,yannick/h2o,devnexen/h2o,cwyang/h2o,devnexen/h2o,yannick/h2o,h2o/h2o,cwyang/h2o,yannick/h2o,h2o/h2o,yannick/h2o,h2o/h2o,yannick/h2o,cwyang/h2o,yannick/h2o,h2o/h2o,h2o/h2o