score calculation

Rewritten-docs.md

@@ -2345,7 +2345,23 @@ Roles description:
 
 ## Writing score configuration
 
-@todo: introduction to scoring, mention that there can be more implementation but for now only simple is available
+Important thing about assignment is how to assign points to particular
+solutions. As mentioned previously whole job is composed of logical tests. All
+of these tests have to contain one essential "evaluation" task. Evaluation task
+should output one float number which can be further used for scoring of
+particular tests.
+
+Total resulting score of the students solution is then calculated according to a
+supplied score config (described below) and using specified calculator. Total
+score is also a float between 0 and 1. This number is then multiplied by the
+maximum of points awarded for the assignment by the teacher assigning the
+exercise -- not the exercise author.
+
+For now there is only one way how to write score configuration using only simple
+score calculator. But the implementation in API is agile enough to handle
+upcoming score calculators which might use some more complex scoring algorithms.
+This also means that future calculators do not have to use YAML format as the
+already defined one, but can use its own or different one.
 
 ### Simple score calculation
 
@@ -2488,6 +2504,10 @@ the output length (as long as the printing fits in the time limit).
       limits:
           - hw-group-id: group1
             chdir: ${EVAL_DIR}
+            bound-directories:
+                - src: ${SOURCE_DIR}
+                  dst: ${EVAL_DIR}
+                  mode: RW
             time: 0.5
             memory: 8192
 ```
@@ -2528,7 +2548,11 @@ used.
       name: "isolate"
       limits:
           - hw-group-id: group1
-            chdir: ${EVAL_DIR} 
+            chdir: ${EVAL_DIR}
+            bound-directories:
+                - src: ${SOURCE_DIR}
+                  dst: ${EVAL_DIR}
+                  mode: RW
 ```