feat: Spring Boot config files in repos

application*.properties/.yml and bootstrap* files tracked by git are
listed under Repos, with their secret-looking keys as secrets.

- Keys whose name ends like a secret (password, secret, token, key, …)
  or whose value looks like one (Jasypt ENC(...), a URL or connection
  string with a password) are listed; providers.repos.spring.keys and
  .values replace the patterns, also in a repo's .lazysecrets.yaml.
- A file's details count the keys left out; ${VAR} values are marked
  as references, and a tracked file is only marked red when a listed
  value is in plain text.
- Later YAML/properties documents name their keys after the profile:
  spring.datasource.password (prod).
- Maven's @placeholders@ parse; Argo CD's applications.yaml and Helm
  templates aren't Spring files.
- A green leaf icon, themeable with springColor.

README.md

@@ -23,7 +23,7 @@ A terminal UI for finding, reading and sharing secrets. Inspired by the fantasti
 - **Your way**: rebind any key, pick a theme, and add custom commands to run
   on a secret.
 - **Try it first**: `lazysecrets --demo` runs on built-in sample data.
-- **Sources**: Azure Key Vault, Databricks secret scopes, and SOPS and `.env` files in your git repos.
+- **Sources**: Azure Key Vault, Databricks secret scopes, and SOPS, `.env` and Spring Boot config files in your git repos.
 
 > **Early development:** expect rough edges. See [CHANGELOG.md](CHANGELOG.md) for what's new.
 
@@ -87,7 +87,7 @@ pickers and scripts: see [Integration](docs/integration.md#an-fzf-picker).
 - [Keys](docs/keys.md): every key, Go to, the layout, and rebinding keys
 - [Azure Key Vault](docs/azure.md): accounts, permissions, pinned vaults
 - [Databricks](docs/databricks.md): profiles and Key Vault-backed scopes
-- [SOPS and .env files](docs/repos.md): which repos and files, decrypting
+- [SOPS, .env and Spring files](docs/repos.md): which repos and files, decrypting
 - [Sharing](docs/sharing.md): links to secrets, encrypted env files, and
   opening links, also from the browser and chat
 - [Integration](docs/integration.md): how lazysecrets can integrate into other systems