feat(example): added an example of packaging a rust app from github (#124)

* better caching when building docker images for app

Reviewed-on: NationTech/harmony#124
Reviewed-by: johnride <jg@nationtech.io>
Co-authored-by: Willem <wrolleman@nationtech.io>
Co-committed-by: Willem <wrolleman@nationtech.io>

Cargo.lock

@@ -1838,6 +1838,21 @@ dependencies = [
  "url",
 ]
 
+[[package]]
+name = "example-try-rust-webapp"
+version = "0.1.0"
+dependencies = [
+ "base64 0.22.1",
+ "env_logger",
+ "harmony",
+ "harmony_cli",
+ "harmony_macros",
+ "harmony_types",
+ "log",
+ "tokio",
+ "url",
+]
+
 [[package]]
 name = "example-tui"
 version = "0.1.0"
@@ -2318,6 +2333,7 @@ dependencies = [
  "tokio-util",
  "url",
  "uuid",
+ "walkdir",
 ]
 
 [[package]]
@@ -4955,6 +4971,15 @@ dependencies = [
  "cipher",
 ]
 
+[[package]]
+name = "same-file"
+version = "1.0.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "93fc1dc3aaa9bfed95e02e6eadabb4baf7e3078b0bd1b4d7b6b0b68378900502"
+dependencies = [
+ "winapi-util",
+]
+
 [[package]]
 name = "schannel"
 version = "0.1.27"
@@ -6494,6 +6519,16 @@ dependencies = [
  "libc",
 ]
 
+[[package]]
+name = "walkdir"
+version = "2.5.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "29790946404f91d9c5d06f9874efddea1dc06c5efe94541a7d6863108e3a5e4b"
+dependencies = [
+ "same-file",
+ "winapi-util",
+]
+
 [[package]]
 name = "want"
 version = "0.3.1"
@@ -6676,6 +6711,15 @@ version = "0.4.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "ac3b87c63620426dd9b991e5ce0329eff545bccbbb34f3be09ff6fb6ab51b7b6"
 
+[[package]]
+name = "winapi-util"
+version = "0.1.10"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0978bf7171b3d90bac376700cb56d606feb40f251a475a5d6634613564460b22"
+dependencies = [
+ "windows-sys 0.60.2",
+]
+
 [[package]]
 name = "winapi-x86_64-pc-windows-gnu"
 version = "0.4.0"