docs: add bectl chapter

docs/src/SUMMARY.md

@@ -8,8 +8,8 @@
     - [Design Overview](./betree/design.md)
     - [Known Bugs](./betree/bugs.md)
   - [bectl](./bectl.md)
-    - [Build & Test]()
-    - [Basic Usage]()
+    - [Build & Test](./bectl/build.md)
+    - [Basic Usage](./bectl/usage.md)
   - [julea-betree](./julea-betree.md)
     - [Build]()
     - [Usage in JULEA]()

docs/src/bectl.md

@@ -1 +1,7 @@
 # bectl
+
+This application allows for usage with an CLI albeit suboptimally as the
+complete stack has to be reinitialized on each access. It is best fit for
+debugging at the moment and demonstration purposes.
+
+We shortly demonstrate how to build it and how to configure and use it.

docs/src/bectl/build.md

@@ -0,0 +1,20 @@
+# Build & Test
+
+
+Building `bectl` is relatively simple but does require all dependencies of
+`betree_storage_stack` to be available. If you have not done this yet refer to
+the [Building chapter](../build.md).
+
+Given all prerequisites are fulfilled simply run
+
+```sh
+$ cargo build
+```
+
+from the `bectl` directory to build bectl on its own.
+
+--- 
+
+There are not yet any tests provided for the `bectl` as the functionality is a
+rather simple mapping to `betree_storage_stack` functions. If we want to expand
+this in the future we might want to ensure that.

docs/src/bectl/usage.md

@@ -0,0 +1,2 @@
+# Basic Usage
+