fossil-add: add page (#7108)

pages/linux/fossil-add.md

@@ -0,0 +1,12 @@
+# fossil add
+
+> Put files or directories under Fossil version control.
+> More information: <https://fossil-scm.org/home/help/add>.
+
+- Put a file or directory under version control, so it will be in the current checkout:
+
+`fossil add {{path/to/file_or_directory}}`
+
+- Remove all added files from the current checkout:
+
+`fossil add --reset`