This is just the commands
/flide2for Elytra Flight that will launch you into the air and push you along.
/flidewill push you at a sustained continual speed, while
/flide2will apply a slow acceleration (feels a bit more like flying a plane).
Hold the sneak key (shift) at any time to end the acceleration so you can land.
Flide script haste: https://one.denizenscript.com/haste/73042 (<-- use this link to download the script)