Move crates under substreams directory.

This way we can run GHA jobs depending on what files changed.

substreams/crates/tycho-substreams/rustfmt.toml

@@ -0,0 +1,13 @@
+reorder_imports = true
+imports_granularity = "Crate"
+use_small_heuristics = "Max"
+comment_width = 100
+wrap_comments = true
+binop_separator = "Back"
+trailing_comma = "Vertical"
+trailing_semicolon = false
+use_field_init_shorthand = true
+chain_width = 40
+ignore = [
+    "src/pb",
+]