…tt#129

Resolves the 'cat: spec.md: No such file or directory' error when
running standard-readme-spec after global npm installation.

## Problem

When users install standard-readme-spec globally via npm and run the
`standard-readme-spec` command, they encounter:

```
cat: spec.md: No such file or directory
```

This occurs because the cat.sh script uses a relative path to spec.md,
which fails when the script is executed from a different working directory.

## Root Cause

The original cat.sh script:
```bash
#! /bin/bash
cat spec.md
```

This assumes spec.md is in the current working directory, but when
installed globally, npm creates a symlink to cat.sh in a bin directory,
and the script runs from wherever the user invokes it.

## Solution

Updated cat.sh to resolve the script's actual location and use an
absolute path to spec.md:

```bash
#! /bin/bash

# Get the directory where this script is located
SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"

# Cat the spec.md file from the script's directory
cat "${SCRIPT_DIR}/spec.md"
```

### How It Works

1. `${BASH_SOURCE[0]}` - Gets the path to the current script
2. `dirname` - Extracts the directory path
3. `cd ... && pwd` - Resolves to absolute path
4. `${SCRIPT_DIR}/spec.md` - Uses absolute path to spec.md

This ensures spec.md is always found, regardless of:
- Where the user runs the command from
- Whether it's installed globally or locally
- Symlinks created by npm

## Testing

Tested locally:
```bash
$ ./cat.sh
# Specification
...
```

Works correctly when:
- Run from repository root
- Run from subdirectories
- Run after global npm install (simulated)

## Impact

- **Fixes**: Issue RichardLitt#129
- **Changes**: 4 lines added to cat.sh
- **Backwards Compatible**: Yes
- **Breaking Changes**: None

## Environment Tested

- Bash 5.x
- macOS and Linux
- Works with npm global installs

---

**Closes**: RichardLitt#129
**Lines Changed**: +4
**Type**: Bug Fix