Revert "Source based weaver (MirrorNetworking#319)"

This reverts commit 8d7613b.

Update Migration.md (MirrorNetworking#401)

Added `cs` and code block formatting

Update README.md to improve Usage Guide guidelines (MirrorNetworking#402

)

* Update README.md to improve Usage Guide guidelines

Submitting for review by the team. This is my suggestion for updating the Usage section due to struggles we have seen in the help channel.

* Update README.md

Missed a character

* Update README.md

Updated Unity version numbers

Configurable Server Tickrate (MirrorNetworking#390)

* Configurable Server Tickrate

* only  Update

Update Attributes.md (MirrorNetworking#398)

Removed NetworkHash128 and NetworkInstanceId from the types list.

Update SyncLists.md (MirrorNetworking#397)

Cleaned up type list and indentations / formatting
Added comment about using OnStartClient vs Start

Update SpawnObjectCustom.md (MirrorNetworking#396)

Replaced `NetworkHash128` with `System.Guid`
Added `cs` to code blocks

Update RemoteActions.md (MirrorNetworking#395)

Removed NetworkHash128 and NetworkInstanceId from the list of allowed arguments
Added `cs` to code samples.

Update StateSync.md (MirrorNetworking#394)

Fixed title capitalization and changed example to OnStartClient instead of Start

Callback functionality was incorrectly represented (MirrorNetworking#393

)

Callback functionality is achieved through event handling. I've updated the documentation here to better represent a generic SyncList as well as a custom data type.