Consolidate common Rust gitignore directives (#1459)

Author: AaronRM

rust/beaubourg/.gitignore renamed to rust/.gitignore

@@ -1,11 +1,13 @@
-# Generated by Cargo
-# will have compiled files and executables
-/target/
-crates/*/target/
+# Rust specific
+**/target/
+# These are backup files generated by rustfmt
+**/*.rs.bk
+**/bench-log
 
 # Remove Cargo.lock from gitignore if creating an executable, leave it for libraries
 # More information here https://doc.rust-lang.org/cargo/guide/cargo-toml-vs-cargo-lock.html
-Cargo.lock
-
-# These are backup files generated by rustfmt
-**/*.rs.bk
+#
+# To remove Cargo.lock from a crate-specific gitignore (e.g. for binary crates), use the following:
+#   !*/Cargo.lock
+#
+**/Cargo.lock

rust/experimental/query_abstraction/.gitignore

@@ -1,9 +1,3 @@
-# Rust specific
-/target
-**/*.rs.bk
-Cargo.lock
-bench-log
-
 # Just
 just.zsh