fixing four headings from user-guide page

Author: vsoch

pages/docs/user-docs/user-guide.md

@@ -14,25 +14,25 @@ Over the past decade and a half, virtualization has gone from an engineering toy
 
 For the industry at the forefront of the virtualization front this is a good thing. The enterprise and web enabled cloud requirements are very much in alignment with the feature set of virtual machines, and thus the predeceasing container technologies, but this does not bode as well for the scientific world and specifically the high performance computation (HPC) use case. While there are many overlapping features of these two fields, they differ in ways that make a shared implementation generally incompatible. While some have been able to leverage custom built resources that can operate on a lower performance scale, a proper integration is difficult and perhaps impossible with today's technology.
 
-Scientists are a resourceful bunch and many of the features which exist both purposefully and incidentally via commonly used container technologies are not only desired, they are required for scientific use cases. This is the necessity which drove the creation of Singularity and articulated it's 4 primary functions:
+Scientists are a resourceful bunch and many of the features which exist both purposefully and incidentally via commonly used container technologies are not only desired, they are required for scientific use cases. This is the necessity which drove the creation of Singularity and articulated its four primary functions:
 
-1. **Mobility Of Compute**
+### Mobility Of Compute
 
 Mobility of compute is defined as the ability to define, create and maintain a workflow and be confident that the workflow can be executed on different hosts, operating systems (as long as it is Linux) and service providers. Being able to contain the entire software stack, from data files to library stack, and portably move it from system to system is true mobility.
 
 Singularity achieves this by utilizing a distributable image format that contains the entire container and stack into a single file. This file can be copied, shared, archived, and thus standard UNIX file permissions also apply. Additionally containers are portable (even across different C library versions and implementations) which makes sharing and copying an image as easy as `cp` or `scp` or `ftp`.
 
-2. **Reproducibility**
+### Reproducibility
 
 As mentioned above, Singularity containers utilize a single file which is the complete representation of all the files within the container. The same features which facilitate mobility also facilitate reproducibility. Once a contained workflow has been defined, the container image can be snapshotted, archived, and locked down such that it can be used later and you can be confident that the code within the container has not changed. The container is not subject to any external influence from the host operating system (aside from the kernel).
 
-3. **User Freedom**
+### User Freedom
 
 System integrators, administrators, and engineers spend a lot of effort maintaining the operating systems on the resources they are reasonable for, and as a result tend to take a cautious approach on their systems. As a result, you may see hosts installed with a production, mission critical operating system that is "old" and may not have a lot of packages available for it. Or you may see software or libraries that are too old or incompatible with the software you need to run, or maybe just haven't installed the software stack you need due to complexities with building, specific software knowledge, incompatibilities or conflicts with other installed programs.
 
 Singularity can give the user the freedom they need to install the applications, versions, and dependencies for their workflows without impacting the system in any way. Users can define their own working environment and literally copy that environment image (single file) to a shared resource, and run their workflow inside that image.
 
-4. **Support On Existing Traditional HPC**
+### Support On Existing Traditional HPC
 
 There are a lot of container systems presently available which are designed either for the enterprise, a replacement for virtual machines, cloud focused, or requires kernel features which are either not stable yet, or not available on your distribution of choice (or both).
 
@@ -45,6 +45,7 @@ Singularity can run on host Linux distributions from RHEL6 (RHEL5 for versions l
 
 ## A High Level View of Singularity
 
+
 ### Security and privilege escalation
 
 *A user inside a Singularity container is the same user as outside the container*