Publish GoTips

GoTips are not yet published here and this issue tracks adding them.

I found them particularly helpful to understand Go concepts that are used slightly differently from other languages (e.g. interfaces). I can recall the moment I read `GoTip #49: Accept Interfaces, Return Concrete Types` and it finally clicked. Now as I do code reviews I reference [Go Decisions - Interfaces](https://google.github.io/styleguide/go/decisions#interfaces) but I worry it's not enough.

My request is to find a way to iteratively publish the episodes that are already mentioned in the style guide.

```
- GoTip #1: Line of Sight
- GoTip #3: Benchmarking Go Code
- GoTip #4: Cleaning Up Your Tests
- GoTip #5: Slimming Your Client Libraries
- GoTip #10: Configuration Structs and Flags
- GoTip #13: Designing Errors for Checking
- GoTip #24: Use Case-Specific Constructions
- GoTip #25: Subtests: Making Your Tests Lean
- GoTip #29: Building Strings Efficiently
- GoTip #38: Functions as Named Types
- GoTip #40: Improving Time Testability with Function Parameters
- GoTip #41: Identify Function Call Parameters
- GoTip #42: Authoring a Stub for Testing
- GoTip #44: Improving Time Testability with Struct Fields
- GoTip #48: Error Sentinel Values
- GoTip #50: Disjoint Table Tests
- GoTip #51: Patterns for Configuration
- GoTip #49: Accept Interfaces, Return Concrete Types
- GoTip #78: Minimal Viable Interfaces
- GoTip #80: Dependency Injection Principles
- GoTip #89: When to Use Canonical Status Codes as Errors
- GoTip #106: Error Naming Conventions
- GoTip #110: Don’t Mix Exit With Defer
- GoTip #117: Subtest Names
```