Add module files for several modules

Rename modules, so we have alphabetical order for the modules, which is
way nicer than the current order.

The following modules are added:

    - borrow
    - counter
    - cuecards
    - dairy
    - ledger
    - password
    - weather

Plus, this commit adds an utility module file, where the utility modules
are described

doc/src/06010-module-utils.md

@@ -0,0 +1,8 @@
+## Utils {#sec:modules:utils}
+
+Some utility modules are provided to alter entries directly.
+
+### Link utility {#sec:modules:utils:link}
+
+### Tag utility {#sec:modules:utils:tag}
+

doc/src/06020-module-borrow.md

@@ -0,0 +1,6 @@
+<!--
+
+## Borrow {#sec:modules:borrow}
+
+-->
+

doc/src/06020-module-counter.md

@@ -0,0 +1,4 @@
+## Counter {#sec:modules:counter}
+
+The Counter module.
+

doc/src/06020-module-cuecards.md

@@ -0,0 +1,6 @@
+<!--
+
+## Cuecards {#sec:modules:cuecards}
+
+-->
+

doc/src/06020-module-diary.md

@@ -0,0 +1,6 @@
+<!--
+
+## Diary {#sec:modules:diary}
+
+-->
+

doc/src/06020-module-ledger.md

@@ -0,0 +1,6 @@
+<!--
+
+## Ledger {#sec:modules:ledger}
+
+-->
+

doc/src/06020-module-password.md

@@ -0,0 +1,6 @@
+<!--
+
+## Password {#sec:modules:password}
+
+-->
+

doc/src/06020-module-weather.md

@@ -0,0 +1,6 @@
+<!--
+
+## Weather {#sec:modules:weather}
+
+-->
+