update veins documentation to be accurate!

1.20.x/worldgen/features/veins.md

@@ -20,14 +20,16 @@ All vein features have several common options which apply to all veins:
 - `density`: An optional number in the range [0, 1] (Default: `0.2`).
 - `min_y`: A [Vertical Anchor](../../common-types/#vertical-anchor). The minimum y level at which the vein will spawn.
 - `max_y`: A [Vertical Anchor](../../common-types/#vertical-anchor). The maximum y level at which the vein will spawn.
-- `salt`: An integer which represents a random seed to the vein locations.
-- `biomes`: An optional array of objects, which can have one of two fields. This represents a filter for allowed biomes. If omitted, all biomes will be allowed.
-  - `category`: A [Biome Category](../../common-types/#biome-category).
-  - `biome_dictionary`: A [Biome Dictionary](../../common-types/#biome-dictionary) tag.
+- `project`: An optional boolean (Default: `false`). This adds the height of the world surface to the position the vein will spawn at. This means that `min_y` and `max_y` must then be specified relative to the world surface, rather than as an absolute y level.
+- `project_offset`: An optional boolean (Default: `false`). This offsets the surface height used to make the surface projection when `project` is enabled by a random amount laterally. For example, this might mean that a vein set to spawn a few blocks below the surface may occasionally break the surface, since the projection it is using is no longer completely accurate.
+- `random_name`: Either a string or a long integer. This value should be unique to this configured feature, as it helps randomize the placement of the vein.
+- `biomes`: An optional biome tag. If used, the vein will be restricted to the given biomes.
+- `near_lava`: An optional boolean (Default: `false`). If true, the vein will only spawn if there are lava blocks detected nearby.
 - `indicator`: An optional object representing an indicator to spawn on the surface above the vein. If present, it must have the following fields:
-  - `depth`: An optional positive integer (Default: `35`). The maximum depth below the surface that the vein will spawn an indicator at.
-  - `spread`: An optional positive integer (Default: `15`). The maximum horizontal distance from a vein that can spawn an indicator.
-  - `rarity`: An optional positive integer (Default: `10`). The rarity to spawn indicators, as a fraction of horizontal locations the vein places ore blocks.
+  - `depth`: A positive integer. The maximum depth below the surface that the vein will spawn an indicator at.
+  - `rarity`: A positive integer. The rarity to spawn indicators, as a fraction of horizontal locations the vein places ore blocks.
+  - `underground_rarity`: A positive integer. The rarity to spawn indicators underground when the vein is too deep to spawn on the surface, as a fraction of horizontal locations the vein places ore blocks.
+  - `underground_count`: A positive integer. The number of attempts to spawn an underground indicator in a given location.
   - `blocks`: A [Weighted List](../../common-types/#weighted-list) of indicator states to spawn, with the following value:
     - Value `block`: A [Lenient Blockstate](../../common-types/#lenient-blockstate) to spawn.
 
@@ -57,4 +59,12 @@ A vein that places a tall pipe, that can be skewed or slanted. Skew represents t
   - `max_skew`: An optional positive integer (Default: `0`). The maximum skew of the vein.
   - `min_slant`: An optional positive integer (Default: `0`). The minimum slant of the vein.
   - `max_slant`: An optional positive integer (Default: `0`). The maximum slant of the vein.
-  - `sign`: An optional number in [0, 1] (Default: `0.5`) The sign of the slant.
+  - `sign`: An optional number in [0, 1] (Default: `0.5`) The sign of the slant.
+
+### Kaolin Disc Vein
+
+A vein that places a kaolin clay disc. This is otherwise the same as a disc vein, but ignores the `blocks` field in favor of setting layered clay blocks.
+
+- Type: `tfc:kaolin_disc_vein`
+- Additional Config:
+  - `height`: The height of the disc. The `size` parameter is interpreted as the radius.