pushd: added platform specific examples in windows, osx and linux. Removed from common. (#1535)

pages/linux/pushd.md

@@ -1,6 +1,7 @@
 # pushd
 
 > Place a directory on a stack so it can be accessed later.
+> See also `popd` to switch back to original directory.
 
 - Switch to directory and push it on the stack:
 

pages/osx/pushd.md

@@ -0,0 +1,16 @@
+# pushd
+
+> Place a directory on a stack so it can be accessed later.
+> See also `popd` to switch back to original directory.
+
+- Switch to directory and push it on the stack:
+
+`pushd < {{directory}}`
+
+- Switch first and second directories on the stack:
+
+`pushd`
+
+- Rotate stack by making the 5th element the top of the stack:
+
+`pushd +4`

pages/windows/pushd.md

@@ -0,0 +1,8 @@
+# pushd
+
+> Place a directory on a stack so it can be accessed later.
+> See also `popd` to switch back to original directory.
+
+- Switch to directory and push it on the stack:
+
+`pushd {{directory}}`