[doc] update documentation (#6)

Author: golanglibs

README.md

@@ -1 +1,69 @@
 # goassert
+
+`goassert` is a simple assertion library for go/golang.
+It does not try to do anything fancy and keeps things as simple as possible.
+Its primary goal is to make assertions as short and simple as possible.
+It also takes advantage of go generics as much as possible to be able to handle as many types as possible
+with as fewest assertion methods as possible
+
+## Installation
+```bash
+go get -t -u github.com/golanglibs/goassert@latest
+```
+
+## Usage
+```go
+package yourpackage
+
+import (
+	"testing",
+
+	"github.com/golanglibs/goassert"
+)
+
+func Test_1Plus1ShouldEqual2(t *testing.T) {
+	actual := 1 + 1
+	expected := 2
+
+	goassert.Equal(t, expected, actual)
+	// on assertion error
+	// --- FAIL: Test_1Plus1ShouldEqual2 (0.00s)
+	// module_test.go: 11: Expected 2. Actual: 1
+}
+```
+
+## Available Assertions
+
+### Truth
+* `True` - asserts the value is true
+* `False` - asserts the value is false
+
+### Equality
+* `Equal` - asserts two values are equal. Values must be comparable
+* `NotEqual` - asserts two values are not equal. Values must be comparable
+* `Nil` - asserts the value is nil
+* `NotNil` - asserts the value is not nil
+* `EqualSlice` - asserts two slices have the same values in the same order. The elements must be comparable
+* `NotEqualSlice` - asserts two slices do not have the same values in the same order. The elements must be comparable
+* `SimilarSlice` - asserts two slices have the same values in either different or same order. The elements must be comparable
+* `NotSimilarSlice` - asserts two slices do not have the same values. The elements must be comparable
+* `EqualMap` - asserts two maps have same key-value pairs. The values must be comparable
+* `NotEqualMap` - asserts two maps do not have same key-value pairs. The values must be comparable
+
+### Collection
+* `EmptySlice` - asserts the slice is empty. The assertion will fail if the slice is nil
+* `NotEmptySlice` - asserts the slice is not nil or empty
+* `SliceLength` - asserts the slice has the specified length
+* `SliceContains` - asserts the slice contains the specified value. The value must be comparable
+* `SliceNotContains` - asserts the slice does not contain the specified value. The value must be comparable
+* `EmptyMap` - asserts the map is empty. The assertion will fail if the map is nil
+* `NotEmptyMap` - asserts the map is not nil or empty
+* `MapLength` - asserts the map has the specified length
+* `MapContains` - asserts the map contains the specified key-value pair
+* `MapNotContains` - asserts the map does not contain the specified key-value pair
+
+### Panic
+* `Panic` - asserts given function panics
+* `NotPanic` - asserts given function does not panic
+* `PanicWithError` - asserts given function panics with the specified error
+* `NotPanicWithError` - asserts given functoin does not panic with the specified error