message: LD_LIBRARY_PATH note
diff: @@ -19,5 +19,6 @@ To run test http 3 programs (neqo-client and neqo-http3-server):
  You can clone NSS (https://hg.mozilla.org/projects/nss) and NSPR
  (https://hg.mozilla.org/projects/nspr) into the same directory and export an
  enviroment variable called `NSS_DIR` pointing to NSS. This causes the build to
  -use the existing NSS checkout.
  -
  +use the existing NSS checkout. However, in order to run anything that depends
  +on NSS, you need to set `$\[DY]LD\_LIBRARY\_PATH` to point to
  +`$NSS_DIR/../dist/Debug/lib`.
  