[web] Fixed a few dead links.

web/README.md

 ## The big picture
 
-- Development related content such as developer guide, benchmark documentation, tools description, ... will be simple Markdown files in e.g. [/web/content/docs](https://github.com/bilke/ogs/blob/web-hugo/web/content/docs/benchmarks/elliptic/groundwater-flow-neumann.md)
+- Development related content such as developer guide, benchmark documentation, tools description, ... will be simple Markdown files in e.g. [/web/content/docs](https://www.opengeosys.org/docs/benchmarks/elliptic/elliptic-neumann)
 - You can preview documentation locally with [Hugo](https://gohugo.io) – a static site generator
-- You can [mark](https://github.com/bilke/ogs/blob/web-hugo/ProcessLib/GroundwaterFlow/CMakeLists.txt#L80) benchmarks to be automatically and interactively visualized [in the documentation](https://github.com/bilke/ogs/commit/d4fc7d94a3821a6b4483a1d7aeaabd6ee391c449#diff-2f5b1ac2a759aa09b2d3f5cc1ece45ceR108) inside your [browser](https://opengeosys.org/docs/benchmarks/elliptic/groundwater-flow-neumann/#results-and-evaluation) via [vtk.js](https://kitware.github.io/vtk-js/)! 🍻 CURRENTLY DISABLED!
+- You can [mark](https://github.com/bilke/ogs/blob/web-hugo/ProcessLib/GroundwaterFlow/CMakeLists.txt#L80) benchmarks to be automatically and interactively visualized [in the documentation](https://github.com/bilke/ogs/commit/d4fc7d94a3821a6b4483a1d7aeaabd6ee391c449#diff-2f5b1ac2a759aa09b2d3f5cc1ece45ceR108) inside your [browser](https://www.opengeosys.org/docs/benchmarks/elliptic/elliptic-neumann/#results-and-evaluation) via [vtk.js](https://kitware.github.io/vtk-js/)! 🍻 CURRENTLY DISABLED!
 
 ## Requirements
 

web/content/docs/benchmarks/bgr_verification_examples/mechanics.pandoc

@@ -2,7 +2,6 @@
 date = "2019-04-24T15:15:45+01:00"
 title = "Small deformations: Verification examples by Vogel,Maßmann"
 weight = 50
-project = "SmallDeformation"
 author = "Johannes Herfurth, Jan Thiedau"
 
 [menu]
@@ -11,8 +10,6 @@ author = "Johannes Herfurth, Jan Thiedau"
 
 +++
 
-{{< data-link >}}
-
 These benchmark examples test the implementation of
 small deformations process with analytical solutions
 presented by Vogel/Massmann.
@@ -37,7 +34,7 @@ chapters in the benchmark books.
 |3.15  |           {{< data-link "m3_3Dshearz" "Mechanics/Linear/Orthotropy/m3_3Dshearz.prj" >}}|
 |3.15 (rotated) |  {{< data-link "m3_3Dshearz_rot" "Mechanics/Linear/Orthotropy/m3_3Dshearz_rot.prj" >}}|
 |3.16  |           {{< data-link "m3_3Dtopload" "Mechanics/Linear/Orthotropy/m3_3Dtopload.prj" >}}|
-|3.16 (rotated) |  {{< data-link "m3_3Dtopload_lc" "Mechanics/Linear/Orthotropy/m3_3Dtopload_lc.prj" >}}|
+|3.16 (rotated) |  {{< data-link "m3_3Dtoploadlc" "Mechanics/Linear/Orthotropy/m3_3Dtoploadlc.prj" >}}|
 
 ## References
 

web/content/docs/benchmarks/heat-transport-bhe/3D_BHE_GW_advection.pandoc

@@ -72,8 +72,7 @@ can be found in the following table.
 
 The BHE parameters are only relevant for the numerical model and are adopted
 from the [3D Beier sandbox
-benchmark](https://www.opengeosys.org/docs/benchmarks/heat-transport-bhe/3d_bei
-er_sandbox/).
+benchmark]({{< ref "3D_Beier_sandbox.pandoc" >}}).
 
 {{< img src="../3D_BHE_GW_advection_figures/mesh.png" width="150">}}