Fix unix port directory

Getting-Started.md

@@ -28,7 +28,7 @@ Then, clone the repository to your local machine:
 
 Change directory to the Unix build directory:
 
-> cd ./micropython/unix
+> cd ./micropython/ports/unix
 
 And then make the executable
 
@@ -54,7 +54,7 @@ Clone the git repository to your local machine:
 
 Change directory to the Unix build directory:
 
-> cd ./micropython/unix
+> cd ./micropython/ports/unix
 
 Edit main.c, replacing "malloc.h" with "stdlib.h", then:
 
@@ -76,7 +76,7 @@ Clone the git repository to your local machine:
 
 Change directory to the Unix build directory:
 
-> cd ./micropython/unix
+> cd ./micropython/ports/unix
 
 And then make the executable
 
@@ -106,7 +106,7 @@ Then, clone the repository to your local machine:
 
 Change directory to the Unix build directory:
 
-> cd micropython/unix
+> cd micropython/ports/unix
 
 And then make the executable
 
@@ -139,7 +139,7 @@ Change directory to the git repo and fetch all the submodules:
 
 Change directory to the Unix build directory:
 
-> cd micropython/unix
+> cd micropython/ports/unix
 
 Make the dependencies: