Update ReadMe.md

ReadMe.md

@@ -9,22 +9,22 @@ ROS wrapper to work with [LidarLite](https://gitlab.iri.upc.edu/asantamaria/Lida
 - [iriutils](https://devel.iri.upc.edu/pub/labrobotica/drivers/iriutils/trunk) - IRI C++ library
 
   - Download the library: `svn co https://devel.iri.upc.edu/pub/labrobotica/drivers/iriutils/trunk iriutils`
-  - Compile and install: `cd iriutils/build && cmake -D CMAKE_BUILD_TYPE=RELEASE .. && make && sudo make install`
+  - Compile and install: `cd iriutils/build && cmake -D CMAKE_BUILD_TYPE=RELEASE .. && make -j $(nproc) && sudo make install`
 
 - [comm](https://devel.iri.upc.edu/pub/labrobotica/drivers/comm/trunk) - IRI C++ library
 
   - Download the library: `svn co https://devel.iri.upc.edu/pub/labrobotica/drivers/comm/trunk comm`
-  - Compile and install: `cd comm/build && cmake -D CMAKE_BUILD_TYPE=RELEASE .. && make && sudo make install`
+  - Compile and install: `cd comm/build && cmake -D CMAKE_BUILD_TYPE=RELEASE .. && make -j $(nproc) && sudo make install`
 
 - [usb_i2c_adapter](https://devel.iri.upc.edu/pub/labrobotica/drivers/usb_i2c_adapter/trunk) - IRI C++ library
 
   - Download the library: `svn co https://devel.iri.upc.edu/pub/labrobotica/drivers/usb_i2c_adapter/trunk usb_i2c_adapter`
-  - Compile and install: `cd usb_i2c_adapter/build && cmake -D CMAKE_BUILD_TYPE=RELEASE .. && make && sudo make install`
+  - Compile and install: `cd usb_i2c_adapter/build && cmake -D CMAKE_BUILD_TYPE=RELEASE .. && make -j $(nproc) && sudo make install`
 
 - [LidarLite](https://gitlab.iri.upc.edu/asantamaria/LidarLite) - IRI C++ library
 
   - Download the library: `git clone https://gitlab.iri.upc.edu/asantamaria/LidarLite.git`
-  - Compile and install: `cd LidarLite/build && cmake -D CMAKE_BUILD_TYPE=RELEASE .. && make && sudo make install`
+  - Compile and install: `cd LidarLite/build && cmake -D CMAKE_BUILD_TYPE=RELEASE .. && make -j $(nproc) && sudo make install`
 
 ##### ROS dependencies