[doc] removing details from INSTALL and link to rtd

Author: simogasp

INSTALL.md

@@ -2,6 +2,7 @@
 
 ## Building instructions
 
+For a detailed guide on building the library check the [online documentation](https://cctag.readthedocs.io/).
 
 Required tools:
 * CMake >= 3.14 to build the code
@@ -14,12 +15,6 @@ Optional tool:
 * CUDA >= 9.0 
 Note: On Windows, there are compatibility issues to build the GPU part due to conflicts between msvc/nvcc/thrust/eigen/boost.
 
-### Getting the sources:
-
-```shell
-$ git clone https://github.com/alicevision/CCTag.git
-```
-
 ###  Dependencies
 
 Most of the dependencies can be installed from the common repositories (apt, yum etc):
@@ -29,30 +24,6 @@ Most of the dependencies can be installed from the common repositories (apt, yum
 - OpenCV >= 3.1
 - TBB >= 4.0
 
-On a recent Ubuntu-like distribution (e.g. 14.04), you may want to try to run:
-```shell
-$ sudo apt-get install g++ git-all libpng12-dev libjpeg-dev libeigen3-dev libboost-atomic-dev libboost-chrono-dev libboost-date-time-dev libboost-dev libboost-program-options-dev libboost-exception-dev libboost-filesystem-dev libboost-serialization-dev libboost-system-dev libboost-thread-dev libboost-timer-dev libtbb-dev
-```
-
-OpenCV need to be compiled separately and installed in some `OPENCV_INSTALL` path. Then, when running cmake you need to provide the path to the location where `OpenCVConfig.cmake` is installed, usually `${OPENCV_INSTALL}/share/share/OpenCV/` (see below).
-
-CCTag contains code optimized for AVX2  instruction set, which significantly increases detection performance. You can enable it with the option: `cmake -DCCTAG_ENABLE_SIMD_AVX2=ON`.
-
-----------
-
-### Run the building process
-
-You now just need to be in the CCTag folder and run cmake:
-```bash
-$ mkdir build && cd build
-$ cmake .. -DOpenCV_DIR=${OPENCV_INSTALL}/share/share/OpenCV/
-$ make -j `nproc`
-```
-
-Use `-DCCTAG_WITH_CUDA:BOOL=ON` to enable (default) or disable the cuda support. On Windows, it must be set to `OFF` if the Eigen version is < 3.3.9
-
-If you want to install the library to, say, a CCTAG_INSTALL path, just add `-DCMAKE_INSTALL_PREFIX=$CCTAG_INSTALL` at cmake command line.
-If you want to build CCTag as a shared library: `-DBUILD_SHARED_LIBS=ON`.
 
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