update README to cover cargo install from GH

Author: markgreene74

README.md

@@ -1,25 +1,36 @@
-# pybites_rust
-My solutions for https://rustplatform.com/
+# pybites_rust - Exercise downloader
+Exercise downloader for https://rustplatform.com/
 
-## exercises
+## quickstart
 
-(placeholder)
+- install the `exercise_downloader` directly from GitHub, open a terminal and run:
+    ```shell
+    cargo install --git https://github.com/markgreene74/pybites_rust.git
+    ```
+- cd to the directory where you want to save the exercises
+- run the downloader
+    ```shell
+    exercises_downloader
+    ```
 
-## exercises_downloader
+## compile it manually
 
+Maybe you want to have a look at the code, make some changes, try something new.
+
+- clone the repo and cd to the directory project
 - compile the downloader
-```shell
-cd exercises_downloader && \
-    cargo build --release
-```
+    ```shell
+    cd exercises_downloader && \
+        cargo build --release
+    ```
 - cd back to the project main directory
-```shell
-cd ..
-```
+    ```shell
+    cd ..
+    ```
 - run the downloader from the project main directory
-```shell
-./exercises_downloader/target/release/exercises_downloader
-```
+    ```shell
+    ./exercises_downloader/target/release/exercises_downloader
+    ```
 - the downloader will create `exercises` in the current directory
 
 Alternatively, use the Makefile
@@ -29,8 +40,27 @@ make download-exercises
 
 <details><summary>(Output example ...)</summary>
 
+Using `cargo` to install it from GitHub.
+
+```shell
+➜ cargo install --git https://github.com/markgreene74/pybites_rust.git
+    Updating git repository `https://github.com/markgreene74/pybites_rust.git`
+  Installing exercises_downloader v0.1.0 (https://github.com/markgreene74/pybites_rust.git#d1afb2ec)
+
+(...)
+
+
+   Compiling exercises_downloader v0.1.0 (/my/home/.cargo/git/checkouts/pybites_rust-b497f94da89af8aa/d1afb2e/exercises_downloader)
+    Finished `release` profile [optimized] target(s) in 15.61s
+  Installing /my/home/.cargo/bin/exercises_downloader
+   Installed package `exercises_downloader v0.1.0 (https://github.com/markgreene74/pybites_rust.git#d1afb2ec)` (executable `exercises_downloader`)                                                                                                /15.8s
+
+➜
+```
+
+Using `make` to compile and execute the exercise downloader.
+
 ```shell
-pybites_rust [ main][+]
 ➜ make download-exercises
 make build-executable && \
 exercises_downloader/target/release/exercises_downloader && \