Fix typo in documents (#3473)

Author: TianlongLiang

gitbook/basics/getting-started/host_prerequsites.md

@@ -11,7 +11,7 @@ apt-get update \
   libgcc-9-dev lib32gcc-9-dev lsb-release \
   ninja-build ocaml ocamlbuild python2.7 \
   software-properties-common tree tzdata \
-  unzip valgrind vim wget zip --no-install-recommen
+  unzip valgrind vim wget zip --no-install-recommends
 ```
 
 Then install CMake and wasi-sdk-16.0

gitbook/basics/getting-started/on_host.md

@@ -14,7 +14,7 @@ make
 Then you are ready to go to the directory that contains the hello world program and copy our iwasm vmcore
 
 ```sh
-cp iwasm ../../app-samples/hello-world
+cp iwasm ../../../app-samples/hello-world
 cd ${WAMR-dir}/product-mini/app-samples/hello-world
 ./build.sh
 ```