Update Dokka version to 2.0.0-Beta

Update Kotlin/Dokka version references to 1.9.20 (Kotlin#3510)

(cherry picked from commit 7ccc48e)

Update Dokka's references to 1.9.10 (Kotlin#3210)

(cherry picked from commit 9bbcc21)

Update Dokka's references to 1.9.0

Update Dokka's references to 1.8.20 (Kotlin#3028)

(cherry picked from commit bb1c151)

Do no render Types tab when there are no types (Kotlin#2900)

(cherry picked from commit dca5c31)

Change log level to INFO for messages about alpha plugin versions (Ko…

…tlin#2693)

(cherry picked from commit 8317436)

Update references and documentation to Dokka 1.7.10 (Kotlin#2567)

Update documentation and examples to Dokka 1.7.0 (Kotlin#2542)

(cherry picked from commit fc86d21)

Update documentation and examples to Dokka 1.6.21 (Kotlin#2465)

(cherry picked from commit 52d066c)