Change Japanese manual/toc.md to manual/toc.yml

[VaclavElias]

toc.md needs to be ported to toc.yml so the Japanese side menu is generated instead of default English.

[VaclavElias]

We have this translated JP file https://github.com/stride3d/stride-docs/blob/master/jp/manual/toc.md which needs to be migrated to https://github.com/stride3d/stride-docs/blob/master/jp/manual/toc.yml, and updated/translated to Japanese according this EN file https://github.com/stride3d/stride-docs/blob/master/en/manual/toc.yml