Added divide and modulo operators (#1593)

* Added divide operator (#49)

* Tidy up divide operator logic

* Added modulo operator

* Fix divide test typo

* Add divide by zero test

* Handle int modulo by 0 and add tests

* Tidy up divide/modulo operator node creation

* Fix linter errors

pkg/yqlib/doc/operators/divide.md

@@ -0,0 +1,56 @@
+
+## String split
+Given a sample.yml file of:
+```yaml
+a: cat_meow
+b: _
+```
+then
+```bash
+yq '.c = .a / .b' sample.yml
+```
+will output
+```yaml
+a: cat_meow
+b: _
+c:
+  - cat
+  - meow
+```
+
+## Number division
+The result during division is calculated as a float
+
+Given a sample.yml file of:
+```yaml
+a: 12
+b: 2.5
+```
+then
+```bash
+yq '.a = .a / .b' sample.yml
+```
+will output
+```yaml
+a: 4.8
+b: 2.5
+```
+
+## Number division by zero
+Dividing by zero results in +Inf or -Inf
+
+Given a sample.yml file of:
+```yaml
+a: 1
+b: -1
+```
+then
+```bash
+yq '.a = .a / 0 | .b = .b / 0' sample.yml
+```
+will output
+```yaml
+a: !!float +Inf
+b: !!float -Inf
+```
+

pkg/yqlib/doc/operators/modulo.md

@@ -0,0 +1,72 @@
+
+## Number modulo - int
+If the lhs and rhs are ints then the expression will be calculated with ints.
+
+Given a sample.yml file of:
+```yaml
+a: 13
+b: 2
+```
+then
+```bash
+yq '.a = .a % .b' sample.yml
+```
+will output
+```yaml
+a: 1
+b: 2
+```
+
+## Number modulo - float
+If the lhs or rhs are floats then the expression will be calculated with floats.
+
+Given a sample.yml file of:
+```yaml
+a: 12
+b: 2.5
+```
+then
+```bash
+yq '.a = .a % .b' sample.yml
+```
+will output
+```yaml
+a: !!float 2
+b: 2.5
+```
+
+## Number modulo - int by zero
+If the lhs is an int and rhs is a 0 the result is an error.
+
+Given a sample.yml file of:
+```yaml
+a: 1
+b: 0
+```
+then
+```bash
+yq '.a = .a % .b' sample.yml
+```
+will output
+```bash
+Error: cannot modulo by 0
+```
+
+## Number modulo - float by zero
+If the lhs is a float and rhs is a 0 the result is NaN.
+
+Given a sample.yml file of:
+```yaml
+a: 1.1
+b: 0
+```
+then
+```bash
+yq '.a = .a % .b' sample.yml
+```
+will output
+```yaml
+a: !!float NaN
+b: 0
+```
+