[esp] Add Rust no-std example.

esp/rust/02_esp-gen-no-std/.gitignore

@@ -0,0 +1,19 @@
+# will have compiled files and executables
+debug/
+target/
+.vscode/
+.zed/
+.helix/
+
+# These are backup files generated by rustfmt
+**/*.rs.bk
+
+# MSVC Windows builds of rustc generate these, which store debugging information
+*.pdb
+
+# RustRover
+#  JetBrains specific template is maintained in a separate JetBrains.gitignore that can
+#  be found at https://github.com/github/gitignore/blob/main/Global/JetBrains.gitignore
+#  and can be added to the global gitignore or merged into this file.  For a more nuclear
+#  option (not recommended) you can uncomment the following to ignore the entire idea folder.
+#.idea/