- a wiki location seems to be more reasonable

Separate page for "running"

- collect information for shell session and openfoam-selector, which
  was previously scatttered in various places

Rename "page-build-code" to "building", with symlink for old location

Misc style changes

home.md

-<!-- --- title: OpenFOAM -->
+<!-- --- title: OpenFOAM wiki -->
 
-## About [![OpenFOAM](/icons/nabla.png "OpenFOAM")](http://www.openfoam.com)
+## [![OpenFOAM](/icons/nabla.png "OpenFOAM")](http://www.openfoam.com) About
 
 This wiki provides information to users about
 [accessing](/page-access-code),
-[building](/page-build-code),
+[building](/building),
 [upgrading](/guides/upgrade/upgrade)
 to the latest version of [OpenFOAM](http://www.openfoam.com).
 
 
 | Information         | Comments            |
 |---------------------|---------------------|
-| [![readme](/icons/columns.svg "readme")][foam-readme] [**Readme**][foam-readme] | Further cross-links in the OpenFOAM repository to _system requirements_ etc. |
-| [![repo](/icons/gitlab.svg "repositories")](/page-access-code) [**Access**](/page-access-code) the code | Locations and descriptions of branch names |
-| [![build](/icons/cpu.svg "build")](/page-build-code) [**Build**](/page-build-code) from source | Information about building and links to build or packaging systems |
+| [![readme](/icons/book-open.svg "readme")][foam-readme] [**Readme**][foam-readme] | Further cross-links in the OpenFOAM repository to _system requirements_ etc. |
+| [![repo](/icons/gitlab.svg "repositories")](/page-access-code) [**Access**](/page-access-code) the code | Locations and descriptions of repository branch names |
+| [![build](/icons/cpu.svg "build")](/building) [**Build**](/building) from source | Information about building and links to build or packaging systems |
 | [![upgrade](/icons/chevrons-up.svg "upgrade guide")][upgrade-guide] [**Upgrade**][upgrade-guide] guides | User and developer information for upgrading cases and code to more recent releases |
+| [![run](/icons/play.svg "run")](/running) [**Run**](/running) OpenFOAM | Using the OpenFOAM environment |
 | [![download](/icons/download.svg "download")][download-source] [**Download**][download-source] source packs | Download shortcuts: https://dl.openfoam.com/source/ |
 
 
-## Repositories [![repo](/icons/gitlab.svg "repositories")][all-repos]
+## [![repo](/icons/gitlab.svg "repositories")][all-repos] Repositories
 
 The [develop.openfoam.com site][all-repos] hosts the ***publicly
 accessible*** repositories:
@@ -30,7 +31,7 @@ accessible*** repositories:
 | Additional [modules][all-modules] | _individual_ |
 
 
-## Linux binaries [![packages](/icons/package.svg "packages")](/precompiled)
+## [![packages](/icons/package.svg "packages")](/precompiled) Linux binaries
 
 [***Pre-compiled binary packages***](/precompiled) may be available for
 select Linux systems:
@@ -42,7 +43,7 @@ select Linux systems:
 | [CentOS/RedHat/Fedora](/precompiled/redhat) |
 
 
-## Coding ![code](/icons/code.svg "code")
+## [![coding](/icons/code.svg "code")](#coding) Coding
 
 |               | Comments      |
 |---------------|---------------|
@@ -51,7 +52,7 @@ select Linux systems:
 | [![code style](/icons/italic.svg "code style")][code-style] [Coding Style][code-style] | coding style in OpenFOAM |
 
 
-## Feedback ![feedback](/icons/message-square.svg "feedback")
+## [![Feedback](/icons/message-square.svg "")](#feedback) Feedback
 
 Users can provide feedback by [_submitting issues_](/Submitting-issues)
 or by [_feature requests_](/page-feature-requests).