Fix: Switch the default theme from light mode to dark mode and improve some styles #9869 (#10552)

### What problem does this PR solve?

Fix: Switch the default theme from light mode to dark mode and improve
some styles #9869
-Update UI component styles such as input boxes, tables, and prompt
boxes
-Optimize login page layout and style details
-Revise some of the wording, such as uniformly changing "data flow" to
"pipeline"
-Adjust the parser to support the markdown type

### Type of change

- [x] Bug Fix (non-breaking change which fixes an issue)

web/src/locales/en.ts

@@ -300,8 +300,8 @@ export default {
       dataFlowPlaceholder: 'Please select a pipeline.',
       buildItFromScratch: 'Build it from scratch',
       dataFlow: 'Pipeline',
-      parseType: 'Parse Type',
-      manualSetup: 'Manual Setup',
+      parseType: 'Ingestion pipeline',
+      manualSetup: 'Choose pipeline',
       builtIn: 'Built-in',
       titleDescription:
         'Update your knowledge base configuration here, particularly the chunking method.',
@@ -477,8 +477,9 @@ This auto-tagging feature enhances retrieval by adding another layer of domain-s
       useGraphRagTip:
         'Construct a knowledge graph over file chunks of the current knowledge base to enhance multi-hop question-answering involving nested logic. See https://ragflow.io/docs/dev/construct_knowledge_graph for details.',
       graphRagMethod: 'Method',
-      graphRagMethodTip: `Light: (Default) Use prompts provided by github.com/HKUDS/LightRAG to extract entities and relationships. This option consumes fewer tokens, less memory, and fewer computational resources.</br>
-        General: Use prompts provided by github.com/microsoft/graphrag to extract entities and relationships`,
+      graphRagMethodTip: `
+      Light: (Default) Use prompts provided by github.com/HKUDS/LightRAG to extract entities and relationships. This option consumes fewer tokens, less memory, and fewer computational resources.</br>
+      General: Use prompts provided by github.com/microsoft/graphrag to extract entities and relationships`,
       resolution: 'Entity resolution',
       resolutionTip: `An entity deduplication switch. When enabled, the LLM will combine similar entities - e.g., '2025' and 'the year of 2025', or 'IT' and 'Information Technology' - to construct a more accurate graph`,
       community: 'Community reports',
@@ -1740,7 +1741,7 @@ This delimiter is used to split the input text into several text pieces echo of
       overlappedPercent: 'Overlapped percent (%)',
       searchMethod: 'Search method',
       searchMethodTip: `Defines how the content can be searched — by full-text, embedding, or both.
-The Tokenizer will store the content in the corresponding data structures for the selected methods.`,
+The Indexer will store the content in the corresponding data structures for the selected methods.`,
       begin: 'File',
       parserMethod: 'Parsing method',
       systemPrompt: 'System Prompt',