Update README.md

README.md

@@ -27,7 +27,7 @@ Build and distribute software with Spack
 ```
 to match the Spack installation directory on the current Collab base container image
 - At the build environment a recent version of gcc must be running. Install the most appropriate gcc version based on the OS of the build environment. Below you can find the instructions to install the appropriate gcc version for CentOS 7 (current OS of Collaboratory base image).
-Instructions to install **"devtoolset-9"** [here](https://linuxize.com/post/how-to-install-gcc-compiler-on-centos-7/)
+Instructions to install **"devtoolset-9"** [here](https://linuxize.com/post/how-to-install-gcc-compiler-on-centos-7/).
 - Then we can start building and installing tools with Spack:
 ```
 spack install arbor %gcc@9.3.1
@@ -37,7 +37,9 @@ spack install nest %gcc@9.3.1 +python
 and perform tests for the installations:
 
 https://docs.arbor-sim.org/en/stable/tutorial/single_cell_model.html
+
 https://neuron.yale.edu/neuron/static/docs/neuronpython/firststeps.html
+
 https://nest-simulator.readthedocs.io/en/nest-2.20.1/auto_examples/one_neuron.html
 
 - After fixing any potential errors for shared libraries (info [1](https://github.com/cdr/code-server/issues/766), [2](https://gcc.gnu.org/onlinedocs/libstdc++/manual/abi.html, [3](https://serverkurma.com/linux/how-to-install-and-update-gcc-on-centos-7/)))