Fix escape sequence usage in strings. Remove unneeded import of os

Rename /config API method to config to match it's purpose. UI is
anyway too generic, and not what it is doing

src/main.py

@@ -1,5 +1,5 @@
 # Standard Packages
-import sys, json, yaml, os
+import sys, json, yaml
 import time
 from typing import Optional
 from pathlib import Path
@@ -38,12 +38,14 @@ web_directory = this_directory / 'interface/web/'
 app.mount("/static", StaticFiles(directory=web_directory), name="static")
 templates = Jinja2Templates(directory=web_directory)
 
+
+# Controllers
 @app.get("/", response_class=FileResponse)
 def index():
     return FileResponse(web_directory / "index.html")
 
 @app.get('/config', response_class=HTMLResponse)
-def ui(request: Request):
+def config(request: Request):
     return templates.TemplateResponse("config.html", context={'request': request})
 
 @app.get('/config/data', response_model=FullConfig)

src/processor/org_mode/orgnode.py

@@ -194,7 +194,7 @@ def makelist(filename):
           n.setHeading(prtysrch.group(2))
 
        # Set SOURCE property to a file+heading based org-mode link to the entry
-       escaped_heading = n.Heading().replace("[","\[").replace("]","\]")
+       escaped_heading = n.Heading().replace("[","\\[").replace("]","\\]")
        n.properties['SOURCE'] = f'[[file:{normalize_filename(filename)}::*{escaped_heading}]]'
 
    return nodelist

src/search_filter/date_filter.py

@@ -32,7 +32,7 @@ class DateFilter:
             return query, entries, embeddings
 
         # remove date range filter from query
-        query = re.sub(f'\s+{self.date_regex}', ' ', query)
+        query = re.sub(rf'\s+{self.date_regex}', ' ', query)
         query = re.sub(r'\s{2,}', ' ', query).strip()  # remove multiple spaces
 
         # find entries containing any dates that fall with date range specified in query