[web] Added page on cli arguments.

web/content/docs/userguide/basics/cli-arguments.md

++++
+date = "2021-05-06T13:00:13+01`:00"
+title = "Command-line arguments"
+author = "Lars Bilke"
+weight = 3
+
+[menu]
+  [menu.userguide]
+    parent = "basics"
++++
+
+The following arguments are available:
+
+```
+$ ogs --help
+
+   --enable-fpe
+     enables floating point exceptions
+
+   --unbuffered-std-out
+     use unbuffered standard output
+
+   --config-warnings-nonfatal
+     warnings from parsing the configuration file will not trigger program
+     abortion
+
+   -l <LOG_LEVEL>,  --log-level <LOG_LEVEL>
+     the verbosity of logging messages: none, error, warn, info, debug, all
+
+   -o <PATH>,  --output-directory <PATH>
+     the output directory to write to
+
+   -p <>,  --xml-patch <>  (accepted multiple times)
+     the xml patch file(s) which is (are) applied (in the given order) to
+     the PROJECT_FILE
+
+   -r <PATH>,  --reference <PATH>
+     Run output result comparison after successful simulation comparing to
+     all files in the given path. This requires test definitions to be
+     present in the project file.
+
+   --,  --ignore_rest
+     Ignores the rest of the labeled arguments following this flag.
+
+   --version
+     Displays version information and exits.
+
+   -h,  --help
+     Displays usage information and exits.
+
+   <PROJECT_FILE>
+     (required)  Path to the ogs6 project file.
+```

web/content/docs/userguide/basics/project-file.md

@@ -2,7 +2,7 @@
 date = "2018-11-14T11:00:13+01`:00"
 title = "Project file syntax"
 author = "Lars Bilke"
-weight = 3
+weight = 4
 
 [menu]
   [menu.userguide]
@@ -76,6 +76,8 @@ Patch files contain `<replace>`, `<add>` and `<remove>`-elements with [XPath](ht
 ogs -p path/to/square_1e0_neumann.xml [other/optional/patch_file.xml] path/to/square_1e0.prj
 ```
 
+Supplied patch files are applied in the given order.
+
 ### Option 2b: Use a patch file directly
 
 If the patch file specifies a `base_file`:

web/content/docs/userguide/troubleshooting/get-support.md

@@ -13,7 +13,7 @@ If you encounter issues using or developing OGS let us know. To help you in the
 
 ### Report contents
 
-- OGS version (e.g. version number or git commit hash)
+- Output of `ogs --version` (e.g. version number or git commit hash and CMake arguments)
 - Where did you obtained the program (e.g. self-compiled or as a binary download from the web site)
 - Operating system / hardware information (e.g. Ubuntu 20.04, Intel i5-10600K, 16 GB Ram)
 - Description of the issue: