Update docs

docs/advanced-concepts.md

@@ -3,7 +3,7 @@ id: advanced-concepts
 title: Advanced concepts
 ---
 
-## Deriving state from external sources (Advanced)
+## Deriving state from external sources
 
 With an additional feature of `get` function above, you can get the state from non-atoms. This can be a Redux store, an RxJS observable, or anything that implements getState & subscribe pair. Here is an atom that derives its state from a Redux store.
 
@@ -13,7 +13,7 @@ import store from './reduxStore'
 const derivedAtom = create((get) => get(store.getState, store.subscribe))
 ```
 
-## Enhanced atoms (Advanced)
+## Enhanced atoms
 
 An enhanced atom is an atom with one or more swapped methods. The most common use case is swapping the default `.set` method of an atom like the following. This technique can be used to create "pass through atoms", that act as a mediators. Most people using **xoid** will not need to write enhanced atoms. 
 
@@ -29,7 +29,7 @@ $thru.update(s => s + 1) // modifications to `$mediator` will be directly forwar
 ```
 > Swapping `.set` also affects `.update`, because it uses `.set` internally. This is an intentional feature.
 
-## Streams (Advanced)
+## Streams
 
 With no arguments used, `create` function produces a special atom called a `Stream`.
 

docs/api-overview.md

@@ -3,7 +3,7 @@ id: api-overview
 title: API Overview
 ---
 
-**xoid** consists of 2 exports: `create`, which is used to create atoms, and `use` which is used to get "usables" of an atom if there are any.
+**xoid** consists of 2 exports: `create`, which is used to create atoms, and `use` which is used to get "usables" of an atom.
 
 Atoms have the following methods:
 

docs/performance-optimizations.md

@@ -18,7 +18,7 @@ console.log($atom.value)
 //  25
 ```
 
-## Lazy evalutation in derived atoms
+## Lazy evaluation in derived atoms
 
 A derived atom can be created by using the callback argument of a state initializer function.
 

docs/quick-tutorial.md

@@ -5,9 +5,6 @@ title: Quick Tutorial
 
 > You can skip this part if you've already read the Github README.
 
-
-## Quick Tutorial
-
 **xoid** has only 2 exports: `create` and `use`. This section will cover them, and the **@xoid/react**.
 
 ### Atom