Improve writing in the RTD (#132)

Author: agoscinski

docs/src/check.ipynb

@@ -32,7 +32,7 @@
    "id": "2",
    "metadata": {},
    "source": [
-    "The purpose of a check is to give students a way to validate their code solutions. The student's code can be validated by providing a list of inputs and references, which are compared to the output of the student's code, or by directly testing certain functional behavior of the code. In cases when reference outputs need to be obfuscated, the outputs that are compared can be passed through a _fingerprint_ function. This notebook goes through each of these features and presents an example."
+    "The purpose of a check is to give students a way to validate their code solutions. The student's code can be validated by providing a list of inputs and reference outputs. Once the student presses on the `Check Code` button, the reference outputs are compared to the outputs of the student's code. Furthermore, in cases when the reference outputs need to be obfuscated so the student does not see the solution, the outputs can be passed through a _fingerprint_ function before validation. Another supported form of validation is to test functional behavior of the student's code, for example identity checks. This notebook goes through each of these features and presents an example."
    ]
   },
   {

docs/src/exercises.ipynb

@@ -34,7 +34,7 @@
    "id": "2",
    "metadata": {},
    "source": [
-    "The scicode-widgets mainly offers a flexible code widget that allows instant feedback to evaluate the code for interactive plots."
+    "scicode-widgets provides a flexible code widget that allows instant feedback to evaluate the code for interactive plots."
    ]
   },
   {
@@ -279,7 +279,7 @@
    "id": "17",
    "metadata": {},
    "source": [
-    "So far we always added the imports required for the code inside the code input. We need to do this because the widget is its creates its own environment (own globals), so no function from the notebook is accidently used. However, this does not solve the problem when one wants to include typehints in the function signature that require imports. For this, one can add the library to the globals."
+    "So far we always added the imports required for the code inside the code input. We need to do this because the widget creates its own environment (own globals), so no function from the notebook is accidently used. However, if you want to already provide imports to the user without specifiying them or need them for example for typehints, you can add the library to the `builtins`."
    ]
   },
   {
@@ -328,7 +328,7 @@
    "id": "20",
    "metadata": {},
    "source": [
-    "This is an example how to create a simple exercise using globals in the update function. This can be more convenient in certain cases but a bit more prone to errors as when creating multiple exercises the global names can easily conflict with each other and result in unwanted behavior. Therefore we recommend use the code demo instance that is passed through the update function."
+    "This is an example how to create a simple exercise using globals in the update function. This can be more convenient in certain cases but a bit more prone to errors since when creating multiple exercises the global names can easily conflict with each other and result in unwanted behavior. Therefore we recommend that the code demo instance is used through the update function argument."
    ]
   },
   {