Release 0.3.0-Preview.1

Basic feature with free-slip hydraulic erosion (#1)

Implementing global-local index converter. We are using a pre-computed index table based on the INI parameters.
As revised in the previous version, heightmap generation is now split into configurable stages. Chunk compute and loading process are now separated into different functions.
Improve performance of sparse data copy between host and device.

For more development discussions, please refer to the issue page 👉 #1 (comment)

Data races identified, the same chunk is modified by different threads at the same time, causing some chunks not computed correctly. For a temporary workaround, multithreading is disabled.
Erosion brush calculation is not correct with free-slip range.
Normal map and formatting are not updated after eroding the central chunk, such that chunks are not seamless.
Though not noticable on the generated terrain, erosion brush indices are no longer correct under neighbour chunk logic.
Normal map is not seamless.

User should be given an option to disable free-slip hydraulic erosion. To disable this in the current build, set free slip chunk range to (1,1). However this doesn't effectively prevent the generation of global-local index table, even though global and local index are the same.
Thread model looks excessively complicated.

Improving documentation of how to configure and use the free-slip erosion system.