[Documentation] Replaced the eulerAngle Example with position example (#454)

docs/Learning-Environment-Best-Practices.md

 ## Vector Observations
 * Vector Observations should include all variables relevant to allowing the agent to take the optimally informed decision.
 * Categorical variables such as type of object (Sword, Shield, Bow) should be encoded in one-hot fashion (ie `3` -> `0, 0, 1`).
-* Besides encoding non-numeric values, all inputs should be normalized to be in the range 0 to +1 (or -1 to 1). For example rotation information on GameObjects should be recorded as `AddVectorObs(transform.rotation.eulerAngles.y/180.0f-1.0f);` rather than `AddVectorObs(transform.rotation.y);`. See the equation below for one approach of normalization. 
+* Besides encoding non-numeric values, all inputs should be normalized to be in the range 0 to +1 (or -1 to 1). For example, the `x` position information of an agent where the maximum possible value is `maxValue` should be recorded as `AddVectorObs(transform.position.x / maxValue);` rather than `AddVectorObs(transform.position.x);`. See the equation below for one approach of normalization. 
 * Positional information of relevant GameObjects should be encoded in relative coordinates wherever possible. This is often relative to the agent position.
 
 ![normalization](images/normalization.png)