Improvenents for Documentation

[Sauermann]

While following the configuration instructions in readme.md, I encountered a few issues, where the descriptions seem to be based on previous versions and could be updated to reflect the recent changes. My comments are based on
Jenkins 2.263.1.
phabricator | 86ad69863930 | Oct 19 2020 | b2e96df3a3be
arcanist | ac54d61d7af2 | Oct 19 2020 | 4b3baca999a4

Section "Jenkins Job" Step 3:
Before Step 3 is possible one has to do the following:
In the "General" part of the job-configuration enable "This project is parameterized"

Section "Harbormaster" Step 7:
The Jenkins-Plugin "Build Token Root Plugin" has been renamed and is now called "Build Authorization Token Root".

Section "Harbormaster" Step 7:
In the description it is not mentioned which token (probably the Conduit API Token) should be inserted and at what places the token should be inserted in the Jenkins and Phabricator configuration.

[artms]

PR are welcome :)