chore: improve player manager documentation

[0utplay]

Motivation

The player manager documentation is outdated and often causes issues in our support. This should be updated.

Modification

Updated the documentation of the player manager to provide more information on how to obtain an instance of it.

Result

More and better documentation on how to obtain a player manager instance

[github-actions]

Test Results

 50 files  ±0   50 suites  ±0   1m 20s ⏱️ -10s
446 tests ±0  446 ✅ ±0  0 💤 ±0  0 ❌ ±0 
777 runs  ±0  777 ✅ ±0  0 💤 ±0  0 ❌ ±0 

Results for commit 3fab73a. ± Comparison against base commit 2be2685.

This pull request removes 36 and adds 36 tests. Note that renamed tests count towards both.

eu.cloudnetservice.driver.impl.document.DocumentSerialisationTest ‑ [4] {"b":1,"s":2,"i":3,"l":4,"f":5.0,"d":6.0,"c":"/","string":"Hello, World!","bol":true,"cloud":["Ben?","Yes","No","HoHoHoHo"],"world":{"this":"is","insane":"!","hello":"world"}}, PRETTY
eu.cloudnetservice.driver.impl.document.gson.JavaTimeSerializerTest ‑ [14] 2025-05-13
eu.cloudnetservice.driver.impl.document.gson.JavaTimeSerializerTest ‑ [23] 17:18:46.262608540
eu.cloudnetservice.driver.impl.document.gson.JavaTimeSerializerTest ‑ [28] 17:18:46.262723714Z
eu.cloudnetservice.driver.impl.document.gson.JavaTimeSerializerTest ‑ [29] 17:18:46.262746447Z
eu.cloudnetservice.driver.impl.document.gson.JavaTimeSerializerTest ‑ [30] 17:18:46.262770351+05:00
eu.cloudnetservice.driver.impl.document.gson.JavaTimeSerializerTest ‑ [31] 17:18:46.262786491-03:00
eu.cloudnetservice.driver.impl.document.gson.JavaTimeSerializerTest ‑ [34] 2025-05-13T17:18:46.266943845
eu.cloudnetservice.driver.impl.document.gson.JavaTimeSerializerTest ‑ [39] 2025-05-13T17:18:46.267108141Z
eu.cloudnetservice.driver.impl.document.gson.JavaTimeSerializerTest ‑ [4] 2025-05-13T17:18:46.255258017Z
…

eu.cloudnetservice.driver.impl.document.DocumentSerialisationTest ‑ [4] {"b":1,"s":2,"i":3,"l":4,"f":5.0,"d":6.0,"c":"/","string":"Hello, World!","bol":true,"cloud":["Ben?","Yes","No","HoHoHoHo"],"world":{"hello":"world","this":"is","insane":"!"}}, PRETTY
eu.cloudnetservice.driver.impl.document.gson.JavaTimeSerializerTest ‑ [14] 2025-05-24
eu.cloudnetservice.driver.impl.document.gson.JavaTimeSerializerTest ‑ [23] 18:13:18.047728447
eu.cloudnetservice.driver.impl.document.gson.JavaTimeSerializerTest ‑ [28] 18:13:18.047828042Z
eu.cloudnetservice.driver.impl.document.gson.JavaTimeSerializerTest ‑ [29] 18:13:18.050893867Z
eu.cloudnetservice.driver.impl.document.gson.JavaTimeSerializerTest ‑ [30] 18:13:18.050924303+05:00
eu.cloudnetservice.driver.impl.document.gson.JavaTimeSerializerTest ‑ [31] 18:13:18.050945783-03:00
eu.cloudnetservice.driver.impl.document.gson.JavaTimeSerializerTest ‑ [34] 2025-05-24T18:13:18.051084641
eu.cloudnetservice.driver.impl.document.gson.JavaTimeSerializerTest ‑ [39] 2025-05-24T18:13:18.051239378Z
eu.cloudnetservice.driver.impl.document.gson.JavaTimeSerializerTest ‑ [4] 2025-05-24T18:13:18.044536298Z
…

♻️ This comment has been updated with latest results.