Update configuration option documentation.

- Clean up README formatting.
- Move all configuration documentation from functions into the README.
- Add missing documentation for a bunch of other options.

Fixes #337

functions/fish_prompt.fish

@@ -15,44 +15,8 @@
 #
 #     https://github.com/ryanoasis/nerd-fonts
 #
-# You can override some default prompt options in your config.fish:
+# See README.md for setup and configuration options.
 #
-#     set -g theme_display_git no
-#     set -g theme_display_git_dirty no
-#     set -g theme_display_git_untracked no
-#     set -g theme_display_git_ahead_verbose yes
-#     set -g theme_display_git_dirty_verbose yes
-#     set -g theme_display_git_stashed_verbose yes
-#     set -g theme_display_git_default_branch yes
-#     set -g theme_git_default_branches main trunk
-#     set -g theme_git_worktree_support yes
-#     set -g theme_display_vagrant yes
-#     set -g theme_display_docker_machine no
-#     set -g theme_display_k8s_context yes
-#     set -g theme_display_k8s_namespace no
-#     set -g theme_display_aws_vault_profile yes
-#     set -g theme_display_hg yes
-#     set -g theme_display_virtualenv no
-#     set -g theme_display_virtualenv verbose
-#     set -g theme_display_nix no
-#     set -g theme_display_ruby no
-#     set -g theme_display_go no
-#     set -g theme_display_user ssh
-#     set -g theme_display_hostname ssh
-#     set -g theme_display_sudo_user yes
-#     set -g theme_display_vi no
-#     set -g theme_display_node yes
-#     set -g theme_avoid_ambiguous_glyphs yes
-#     set -g theme_powerline_fonts no
-#     set -g theme_nerd_fonts yes
-#     set -g theme_show_exit_status yes
-#     set -g theme_display_jobs_verbose yes
-#     set -g default_user your_normal_user
-#     set -g theme_color_scheme dark
-#     set -g fish_prompt_pwd_dir_length 0
-#     set -g theme_project_dir_length 1
-#     set -g theme_show_project_parent no
-#     set -g theme_newline_cursor yes
 
 # ==============================
 # Helper methods

functions/fish_right_prompt.fish

@@ -1,6 +1,4 @@
-# You can override some default right prompt options in your config.fish:
-#     set -g theme_date_format "+%a %H:%M"
-#     set -g theme_date_timezone America/Los_Angeles
+# See "Right prompt options" in README.md for configuration options
 
 function __bobthefish_cmd_duration -S -d 'Show command duration'
     [ "$theme_display_cmd_duration" = "no" ]

functions/fish_title.fish

@@ -1,8 +1,4 @@
-# You can override some default title options in your config.fish:
-#     set -g theme_title_display_process no
-#     set -g theme_title_display_path no
-#     set -g theme_title_display_user yes
-#     set -g theme_title_use_abbreviated_path no
+# See "Title options" in README.md for configuration options
 
 function __bobthefish_title_user -S -d 'Display actual user if different from $default_user'
     if [ "$theme_title_display_user" = 'yes' ]