Typos

Rewritten-docs.md

@@ -315,7 +315,7 @@ addons (mostly administrative features).
   solutions are executed to prevent system failures due to malicious code being
   submitted; the sandboxed environment should have the least possible impact on
   measurement results (most importantly on measured times)
-- _heterogenous worker pool_ -- there must be support for submission evaluation
+- _heterogeneous worker pool_ -- there must be support for submission evaluation
   in multiple programming environments in a single installation to avoid
   unacceptable workload for the administrator (maintaining a separate
   installation for every course) and high hardware occupation
@@ -334,10 +334,11 @@ direct mapping to visible parts of the system. In an ideal world, users should
 not know about these features if they work properly, but would be at least
 annoyed if they did not. 
 
-- _no installation_ -- the primary user interface of the system must be accessible
+- _no installation_ -- the primary user interface of the system must be
-  on users' computers without the need to install any additional software
+  accessible on users' computers without the need to install any additional
-- _performace_ -- the system must be ready for at least hundreds of students and
+  software
-  tens of supervisors using it at once
+- _performance_ -- the system must be ready for at least hundreds of students
+  and tens of supervisors using it at once
 - _automated deployment_ -- all of the components of the system must be easy to
   deploy in an automated fashion
 - _open source licensing_ -- the source code should be released under a